refer to exercise 7.11. suppose that in the forest fertilization problem the population standard deviation of basal areas is not known and must be estimated from the sample. if a random sample of n = 9 basal areas is to be measured, find two statistics g1 and g2 such that p (g1 ≤ ( y - u ) ≤ g2 ) = 90

Answer: The answer for the first question goes as follows: Which one(s) have both pairs of opposite sides that are parallel? Rectangle, Rhombus, and square. Which one(s) have both pairs of opposite sides that are congruent? Rectangle, square, and rhombus. Which one(s) have all four sides congruent? Square and rhombus.

The answers to the second question are:

Step-by-step explanation:

Essentially, all of these parallelograms have different properties and properties that they share. For example, a property they share by the definition of a parallelogram is that all of them have two pairs of opposing sides that are parallel. Another property they share from the definition of a parallelogram is that opposite sides are congruent.

As such, rectangles, squares, and rhombuses have the properties that all parallelograms have because they are all parallelograms. However, they also have their own properties.

Second Question Explanation:

1. The question is describing a theater that has a circular base. Therefore, you can use the formula for the circumference of a circle, pi * diameter, to find the circumference (or distance around) the theater. The diameter is given to you: 100 ft. So just multiply that by pi.

2. The question is asking for the area of the theater. This means that you can use the formula for the area of a circle, A = pi * r^2. Note that it is asking you for the area, not the volume, so you would find the area of the circle, not the volume of the hemisphere. r represents the radius of the circle/theater. The diameter is given as 100 ft, and the radius is half of the diameter, so it is 50 ft. Now just plug the radius into the equation and you get the answer I showed.

Answer:

5/7

Step-by-step explanation:

Make all the denominators 42.

26/42, 27/42, 28/42, 29/42

The pattern is the numerator increases by one each time.

30/42 = 5/7

Hope this helps!

Angle of elevation of the ramp with a height of 27ft and a platform of 16ft is approximately 59.35°.

The ramp is 27ft long and rises to a platform, the bottom of the platform is 16ft from the foot of the ramp.

We need to find the angle of elevation of the ramp.

The angle of elevation of the ramp is the angle made by the ramp with the horizontal.

Let ABC be the ramp and D be the platform, as shown below: Let AB = 16ft and BC = 27ft.

We need to find the angle ABD.

Consider right-angled ΔABC In right-angled ΔABC,

we have:

tan⁻¹ (BC / AB)

θ  = tan⁻¹ (27 / 16)

θ ≈ 59.35°

Hence, the angle of elevation of the ramp is approximately 59.35°.

Learn more about Angle of elevation here:

https://brainly.com/question/21137209

#SPJ11

Answer:

$57

Step-by-step explanation:

14% of $50 is:

.14 × 50

= 7

This means the ticket was $7 more.

The price was $50 + $7

Each ticket cost $57.

Answer:

equal

Step-by-step explanation:

The statement that best describes the infοrmatiοn presented in the chart is: "The number οf hurricanes was increasing but has decreased in recent years."

Hurricanes, knοwn generically as trοpical cyclοnes, are lοw-pressure systems with οrganized thunderstοrm activity that fοrm οver trοpical οr subtrοpical waters. They gain their energy frοm warm οcean waters.

The chart shοws the number οf hurricanes οf categοry 1 οr higher that οccurred during specific series οf years, and it indicates that the number οf hurricanes increased frοm 13 in 1980-1989 tο 23 in 2000-2009, and then decreased tο 10 in 2010-2017.

Therefοre, the chart suggests that the number οf hurricanes was increasing, but it has decreased in recent years. The chart dοes nοt prοvide any infοrmatiοn abοut tοrnadοes in Finleyville οr the relatiοnship between the number οf hurricanes and temperature.

To know more about problems related to chart,

https://brainly.com/question/26851221

#SPJ1

The statement that best describes the information in the graph is: "The number of hurricanes has increased but decreased in recent years." The graph shows that the number of Category 1 or greater hurricanes increased from 1980 to 2009, but decreased from 2010 to 2017.

if the members are in tension or compression. Identify all zero force members: Likewise, we can find the reaction force at A by taking minutes about point A: RA x 8m - 5kN x 8m - 5kN x 8m = 0 RA = 5kN

To begin with, we really want to find the reaction forces at An and G.

We can do this by taking minutes about point G.

We realize that the amount of minutes at any point is zero when the framework is in equilibrium.

Consequently, we can compose: 5kN x 8m - RA x 10m = 0 RA = 4kN

Likewise, we can find the reaction force at A by taking minutes about point A: RA x 8m - 5kN x 8m - 5kN x 8m = 0 RA = 5kN

Since we have two distinct qualities for RA, we can presume that the framework isn't in equilibrium.

This really intends that there should be some outside force following up on the framework.

The two obscure forces are at first thought to be ductile (for example pulling away from the joint). In the event that this underlying supposition is mistaken, the registered upsides of the pivotal forces will be negative, meaning pressure.

to know more about forces click here:

https://brainly.com/question/30284058

#SPJ4

the complete question is:

Question l Find the forces in members HE; FH, FE; and FC of the truss as shown in Figure Q1. State if the members are in tension or compression. Identify all zero force members: (10 marks) 8 m 5 KN 8 m 8 m 5 KN 8 m 10 m Figure Q1.

For 95% confidence interval, Standard Error is 3, Margin of Error is 6.4, Lower limit is 65.1 and Upper limit is 77.9.

A confidence interval is a range of values that is likely to contain the true value of an unknown population parameter with a certain degree of confidence based on a sample from that population. It is calculated from the sample data and provides a range of values within which the true population parameter is likely to fall.

1) standard error = s / √(n)

standard error = 12 / √(16)

standard error = 3

2) margin of error = t-value x standard error

margin of error = 2.131 x 3

margin of error = 6.393

3) lower limit = sample mean - margin of error

lower limit = 71.5 - 6.393

lower limit = 65.107

4) upper limit = sample mean + margin of error

upper limit = 71.5 + 6.393

upper limit = 77.893

Therefore, the information for a 95% confidence interval is:

Sample mean = 71.5 pounds

Standard Deviation = 12 pounds

Sample size = 16

Z or t = t

Standard Error = 3

Margin of Error = 6.4

Lower limit = 65.1

Upper limit = 77.9

To know more about confidence interval visit:

https://brainly.com/question/29680703

#SPJ1

The correct option is B) 0.0634.

1) Standard deviationThe table is shown as below:Number of Times Frequency 1 34 2 73 3 249 4 127 5 72 6 30 7 24 Total 915The given population contains 915 people. Let X be the number of times per week a person dines out for a person sampled at random from this population.The population standard deviation is given by the formula below:$$\sigma = \sqrt{\frac{\sum (X-\mu)^2}{N}}$$where N is the population size, X is the value of the individual element of the population, μ is the mean value of the population. $$\sigma = \sqrt{\frac{\sum (X-\mu)^2}{N}}$$$$= \sqrt{\frac{\sum X^2 - 2X\mu + \mu^2}{N}}$$We need to compute the variance first.$$\sigma^2 = \frac{\sum X^2 - 2X\mu + \mu^2}{N}$$$$= \frac{(1^2 \cdot 34 + 2^2 \cdot 73 + 3^2 \cdot 249 + 4^2 \cdot 127 + 5^2 \cdot 72 + 6^2 \cdot 30 + 7^2 \cdot 24) - 2\cdot 3.176 \cdot (34 + 2\cdot 73 + 3\cdot 249 + 4\cdot 127 + 5\cdot 72 + 6\cdot 30 + 7\cdot 24) + 3.176^2 \cdot 915}{915}$$$$= 3.5689$$Therefore, the population standard deviation is given by:$\sigma = \sqrt{3.5689} = 1.8911\approx 1.9$Hence, the correct option is C) 1.92) The probability of a binomial experiment can be calculated by the formula below:$${\rm P}(X=k) = \binom{n}{k}p^k(1-p)^{n-k}$$where n is the number of trials, k is the number of successes, p is the probability of success for each trial, and $1-p$ is the probability of failure for each trial.Here, n = 15 and p = 0.4.We need to find the probability of getting 12 successes out of 15 trials. Hence, k = 12.Using the formula above, we get$${\rm P}(X=12) = \binom{15}{12}0.4^{12}0.6^{3}$$$$= \frac{15 \times 14 \times 13}{3 \times 2 \times 1} \cdot 0.4^{12} \cdot 0.6^{3}$$$$= 0.0633605376$$Hence, the correct option is B) 0.0634.

Learn more about Option

brainly.com/question/22100121

#SPJ11

As the demand for tobacco is inelastic so the consumers are the group who are less responsive to a higher price as an outcome of it the consumers will have to bear the largest share of the tobacco tax.

This inelasticity of demand will lead to only a small decline in the quantity demanded after the tax have been leived , therefore the deadloss weight will be in really small degree. the percentage increase in price of any amount will overcome a smaller decline in the quantity which eventually would lead to a rise in the tax revenue collection.

Inelasticity of demand refers to the degree to which the quantity demanded of a particular good or service changes in response to a change in its price. When demand is inelastic, a change in price will result in a proportionally smaller change in quantity demanded. This is typically the case for goods or services that are considered necessities or have few substitutes available.

For example, if the price of insulin, a life-saving medication for diabetics, increases by 10%, it is unlikely that the quantity demanded will decrease by 10%. People with diabetes require insulin to manage their condition, and there are few substitutes available, so they are willing to pay a higher price to maintain their health.

To learn more about Inelasticity of demand visit here:

brainly.com/question/30103518

#SPJ4

Complete Question: -

Suppose the supply of tobacco is elastic and the demand for tobacco is inelastic. If an excise tax is levied on the suppliers of tobacco, will the incidence fall mostly on consumers or mostly on producers? Will there be a large amount or small amount of deadweight loss? Will tax revenue from the tobacco tax fall or rise?

So, the correct graph should have the scale factor on the x-axis and the area on the y-axis. This is Graph B. The other graphs do not correctly represent the relationship between the scale factor, area, and perimeter.

There are different types of graphs, including directed graphs (also called digraphs), where each edge has a direction, and undirected graphs, where each edge has no direction. Graphs can also be weighted, meaning that each edge has a value associated with it, or unweighted, where all edges have the same value.

Graphs can be represented visually, using diagrams that show the vertices as points and the edges as lines or arrows connecting them. Graphs are used in a variety of applications, including computer algorithms, data analysis, and optimization problems.

by the question.

The area of the original triangle is 6 square inches, and the perimeter is 12 inches. Let the lengths of the sides be a, b, and c. Then, we have:

[tex]a + b + c = 12[/tex] (perimeter)

[tex]s = (a + b + c)/2 = 6[/tex] (semi perimeter)

[tex]A =\sqrt(s(s-a)(s-b)(s-c)) = 6[/tex] (area)

Simplifying the equations, we get:

[tex]a + b + c = 12[/tex]

[tex]a + b + c - 2a - 2b - 2c = 0[/tex]

[tex]-a - b - c = -12[/tex]

[tex]-a - b - c + 2a + 2b + 2c = 0[/tex]

[tex]a + b + c = 0[/tex]

Therefore, the centroid of the original triangle is at the origin (0,0).

When the triangle is dilated by a scale factor of k, the new area and perimeter are given by:

[tex]A' = k^2A = 6k^2[/tex]

[tex]P' = kP = 12k[/tex]

To learn more about scale factor:

https://brainly.com/question/30215044

#SPJ1

As per the distance, the length of the curve y = 3x − 2 for −3 ≤ x ≤ 1 is 4√10.

To begin, let us recall that the arc length formula gives us a way to find the length of a curve in terms of the function that defines it. The formula is given by:

L = ∫aᵇ √[1 + (dy/dx)²] dx

where L is the length of the curve, a and b are the endpoints of the curve, and dy/dx is the derivative of the function that defines the curve with respect to x.

For the curve y = 3x − 2, we can find dy/dx by taking the derivative of the function with respect to x. This gives us:

dy/dx = 3

We can now substitute this into the arc length formula and integrate over the interval −3 ≤ x ≤ 1:

L = ∫−3¹ √[1 + (3)²] dx

L = ∫−3¹ √10 dx

L = √10 ∫−3¹ dx

L = √10 (1 - (-3))

L = √10 (4)

L = 4√10

To know more about distance here

https://brainly.com/question/4199102

#SPJ4

The p-value is greater than the level of significance (0.05). Therefore, we fail to reject the null hypothesis. There is not enough evidence to suggest that the mean time to complete a four-year college degree varies based on gender. The conclusion is that there is no difference between the mean number of years for men and women to complete a four-year college degree.

The null hypothesis in the given data set is there is no difference between the mean number of years for men and women to complete a four-year college degree. The null hypothesis is a statement that describes the population parameter being tested. It is usually given the symbol H0. The null hypothesis is that the population parameter is equal to some value.

The null hypothesis is what is assumed to be true if no evidence is available to contradict it. It can be accepted or rejected based on the results of a statistical test. The degrees of freedom is the number of independent observations in a statistical test. It is usually represented by the symbol df. The degrees of freedom is used to calculate the t-value for a statistical test.

It is calculated as n - 1, where n is the sample size. In this problem, the degrees of freedom is 10 (12 - 2).The t-test is a statistical test used to determine if there is a significant difference between two groups. It is used when the population standard deviation is not known. The t-test uses the t-distribution to determine the p-value. The p-value is the probability of observing the data if the null hypothesis is true.

If the p-value is less than the level of significance, the null hypothesis is rejected. In this problem, the null hypothesis is that there is no difference between the mean number of years for men and women to complete a four-year college degree. To test this hypothesis, we will use a two-sample t-test.

The formula for a two-sample t-test is:t = (x1 - x2) / (s1^2/n1 + s2^2/n2)^(1/2)where x1 is the sample mean for group 1, x2 is the sample mean for group 2, s1 is the sample standard deviation for group 1, s2 is the sample standard deviation for group 2, n1 is the sample size for group 1, n2 is the sample size for group 2, and t is the t-value.

Men: (4 + 5 + 4 + 6 + 4 + 5) / 6 = 28 / 6 = 4.67Women: (6 + 4 + 7 + 5 + 3) / 5 = 25 / 5 = 5The sample mean for men is 4.67 years, and the sample mean for women is 5 years. The pooled variance is a weighted average of the variances of two independent samples. It is used to estimate the population variance when the population variances are assumed to be equal.

The formula for the pooled variance is:s^2 = [(n1 - 1)s1^2 + (n2 - 1)s2^2] / (n1 + n2 - 2)where s1 is the sample standard deviation for group 1, s2 is the sample standard deviation for group 2, n1 is the sample size for group 1, n2 is the sample size for group 2, and s^2 is the pooled variance.s1 = [(4 - 4.67)^2 + (5 - 4.67)^2 + (4 - 4.67)^2 + (6 - 4.67)^2 + (4 - 4.67)^2 + (5 - 4.67)^2] / (6 - 1)^(1/2) = 0.763s2 = [(6 - 5)^2 + (4 - 5)^2 + (7 - 5)^2 + (5 - 5)^2 + (3 - 5)^2] / (5 - 1)^(1/2) = 1.87s^2 = [(6 - 1)0.763^2 + (5 - 1)1.87^2] / (6 + 5 - 2) = 1.243

The t-value is calculated using the formula: t = (x1 - x2) / (s1^2/n1 + s2^2/n2)^(1/2)t = (4.67 - 5) / (1.243/6 + 1.243/5)^(1/2)t = -0.555 The p-value is the probability of observing the data if the null hypothesis is true. The p-value is calculated using a t-table or a t-distribution calculator. The p-value for a two-tailed test with 10 degrees of freedom and a t-value of 0.555 is 0.593.

The p-value is greater than the level of significance (0.05). Therefore, we fail to reject the null hypothesis. There is not enough evidence to suggest that the mean time to complete a four-year college degree varies based on gender. The conclusion is that there is no difference between the mean number of years for men and women to complete a four-year college degree.

Learn more about Null hypothesis

brainly.com/question/28920252

#SPJ11

The area of the region of overlap between the 8-inch by 10-inch paper and the 8(1/2)-inch by 11-inch paper measures 12 square inches.

The area of the region of overlap between an 8-inch by 10-inch paper and an 8(1/2)-inch by 11-inch paper can be found in the following steps:

Step 1: Calculate the area of each paper. The area of an 8-inch by 10-inch paper is:

[tex]$$\text{Area} = \text{length} \times \text{width} = 8 \text{ in.} \times 10 \text{ in.} = 80 \text{ sq. in.}$$[/tex]

The area of an 8 1/2-inch by 11-inch paper is:

[tex]$$\text{Area} = \text{length} \times \text{width} = \left( 8 \frac{1}{2} \right) \text{ in.} \times 11 \text{ in.} = 93.5 \text{ sq. in.}$$[/tex]

Step 2: Find the horizontal and vertical lengths of the region of overlap.

The horizontal length is the length that is common to both papers, which is 8 inches.

The vertical length is the amount by which the two papers overlap, which is 8(1/2) inches - 10 inches = -1(1/2) inches. However, since the region of overlap cannot have a negative length, we take the absolute value of this result, which is 1(1/2) inches.

Step 3: Calculate the area of the region of overlap.

The area of the region of overlap is the product of the horizontal and vertical lengths:

[tex]$$\text{Area of the region of overlap} = 8 \text{ in.} \times 1 \frac{1}{2} \text{ in.} = 12 \text{ sq. in.}$$[/tex]

Therefore, the area of the region of overlap in square inches is 12 square inches.

To know more about the "area of the region" of overlap: https://brainly.com/question/28957662

#SPJ11

An inverse of a modulo m for a = 55, m = 89 using the Euclidean algorithm is 34.

In order to find an inverse of a modulo for each of the following pairs of relatively prime integers using the Euclidean algorithm can be found by:

Using the Euclidean algorithm to find the greatest common divisor (gcd) of a and m. In this case, we have:

89 = 1 x 55 + 34

The gcd of 55 and 89 is 1.

Using the extended Euclidean algorithm, work backwards up the chain of remainders to express 1 as a linear combination of a and m. In this case, we have: 34 x 55 - 21 x 89

   The coefficient of a in the expression from step 3 is the inverse of a modulo m. In this case, the inverse of 55 modulo 89 is 34.

To verify that the inverse is correct, multiply a and its inverse modulo m. The product should be congruent to 1 modulo m. In this case, we have:

   55 x 34 = 1870

   11 = 1 x 11 + 0

Since the remainder is 0, we know that 55 x 34 is a multiple of 89, so it is congruent to 0 modulo 89. Therefore, we have:

55 x 34 ≡ 0 |89|

Adding 89 to the left-hand side repeatedly until we get a number that is congruent to 1 modulo 89, we find:

55 x 34 ≡ 0 + 89 x 7 ≡ 1 |89|

Therefore, the inverse of 55 modulo 89 is indeed 34.

To practice more questions about Euclidean algorithm:

https://brainly.com/question/24836675.

#SPJ11

The probability of at least one of your 10 lottery tickets being a winner is approximately 0.638 or 63.8%.

The probability of winning on a single lottery ticket is 1/8, which means that the probability of not winning is 7/8. If you buy 10 of these lottery tickets, the probability of not winning on any of them is:

(7/8)^10 = 0.362

This means that there is a 36.2% chance that none of your tickets will be a winner. To find the probability that at least one of your tickets will be a winner, we can use the complementary probability:

P(at least one winner) = 1 - P(no winners)

P(at least one winner) = 1 - 0.362

P(at least one winner) = 0.638

Find out more about probability

brainly.com/question/29121185

#SPJ4

The straw would extend approximately 4.9 cm past the edge of the glass.

Answer:

9

Step-by-step explanation:

Answer:

Below in bold.

Step-by-step explanation:

10,16,22,28

16-10 = 6, 22-16 = 6 and 28-22 = 6

This is an arithmetic sequence with first term a1 = 10 and common difference d = 6

General (nth) term = a1 + d(n - 1)

10th term =  10 + 6(9 -1)

                 =  10 + 48

                 = 58.

Answer:

[tex](x + 4)(2x - 5) = 0[/tex]

explanation:

[tex]x \times 2x = 2 {x}^{2} [/tex]

[tex]( - 5 \times x) + (4 \times 2x) = 3x[/tex]

[tex] (- 5) \times 4 = - 20[/tex]

Answer:

10,000

Step-by-step explanation:

1 dekagram = 1000 centigrams

10 dekagrams = 10 x 1000 = 10,000 centigrams

So, the answer is 10,000

[tex]~~~~~~ \textit{Simple Interest Earned} \\\\ I = Prt\qquad \begin{cases} I=\textit{interest earned}\\ P=\textit{original amount deposited}\dotfill & \$115\\ r=rate\to 1.5\%\to \frac{1.5}{100}\dotfill &0.015\\ t=years\dotfill &4 \end{cases} \\\\\\ I = (115)(0.015)(4) \implies I = 6.9[/tex]

Answer:

d(0) = -3

Step-by-step explanation:

d(x) = -x + -3                           d(0)

d(0) = 0 - 3

d(0) = -3

So, the answer is d(0) = -3

The equation is equivalent to pq=r is option (C) q=logR p

To determine which equation is equivalent to pq=r, we can use logarithmic properties. Taking the logarithm of both sides of the equation, we get

log(pq) = log(r)

Using the property that log(a×b) = log(a) + log(b), we can simplify the left side of the equation

log(p) + log(q) = log(r)

Now, we can compare this expression to each of the answer choices

A) p = logR q

Substituting this into the equation, we get

log(p) + logR(q) = log(r)

This is not equivalent to our expression, so A is not the correct answer.

B) p = logQ r

Substituting this into the equation, we get

log(logQ r) + log(q) = log(r)

This is also not equivalent to our expression, so B is not the correct answer.

C) q = logR p

Substituting this into the equation, we get

log(p) + logR(q) = log(r)

This matches our expression, so C is the correct answer.

D) q = logP r

Substituting this into the equation, we get

log(p) + log(q) = log(logP r)

This is not equivalent to our expression, so D is not the correct answer.

Therefore, the correct option is (C)  q=logR p

Learn more about logarithmic properties here

brainly.com/question/30226560

#SPJ4

Answer:

The volume of the sphere 288π cubic meters which is approximately 904.8 cubic meters to the nearest tenth.

Step-by-step explanation:

The given figure is a sphere.

The formula for the volume of a sphere is:

[tex]V=\dfrac{4}{3}\pi r^3[/tex]

where r is the radius.

Given the diameter of the sphere is 12 m, and the radius is half the diameter, r = 6 m.

To calculate the volume of the sphere, substitute r = 6 into the formula:

[tex]\begin{aligned}\implies V&=\dfrac{4}{3}\pi \cdot 6^3\\\\&=\dfrac{4}{3}\pi \cdot 216\\\\&=288\pi \\\\ &\approx 904.8\;\sf m^3\;(nearest\;tenth)\end{aligned}[/tex]

Therefore, the volume of the sphere 288π cubic meters which is approximately 904.8 cubic meters to the nearest tenth.

The values of the provided statics are 8, 4, and 9, but not 12 are solutions to y 9. (For 8, 4, and 9): Answer: No (for 12).

Statics is the study of internal and external forces acting on a structure. Statics is the branch of mechanics that studies bodies in motion. Statics is the study of systems in which momentum does not change, whereas dynamics is the study of systems in which momentum changes.

The values of y that meet the inequality for y 9 are those that fall below or coincide with 9.

y = 8 satisfies y ≤ 9 because 8 is less than 9.

y = 4 satisfies y ≤ 9 because 4 is less than 9.

y = 9 satisfies y ≤ 9 because 9 is equal to 9.

y = 12 does not satisfy y ≤ 9 because 12 is greater than 9.

To know more about statics visit:-

https://brainly.com/question/26609519

#SPJ1

I can give you with a general explanation of the functions of muscles, bones, and sensitive organs, as well as how they work together.

Muscles are responsible for movement and give the force needed to move bones. They're attached to bones via tendons and work in dyads or groups to produce coordinated movement. Muscles are also responsible for maintaining posture and generating heat.

Bones give a rigid frame for the body, cover internal organs, and serve as attachment points for muscles. They also store minerals similar as calcium and produce blood cells in the bone gist.

sensitive organs, similar as the eyes, cognizance, nose, and skin, descry and respond to stimulants in the terrain. They transmit information to the brain, which processes the information and generates an applicable response.

All three body corridor work together in the musculoskeletal system to produce movement, maintain posture, and respond to external stimulants. Muscles attach to bones and work together to produce coordinated movement. sensitive organs descry stimulants in the terrain and transmit information to the brain, which coordinates muscle movement and generates a response. Bones give the rigid frame and attachment points for muscles, as well as cover internal organs.

1. The number of hours which Sidra did on homework is 12 hours

2. The total number of hours which Sally's friends spend on homework per month is 64 hours.

Sidra does 3 keys worth of homework, and since a key equals 4 hours, she does:

= 3 keys x 4 hours/key

= 12 hours of homework.

To find the total number of hours that Sally's friends spend on homework per month, we need to add up the hours of homework done by each of her friends:

Tim: 5 keys x 4 hours/key = 20 hours

Mary: 2 1/2 keys x 4 hours/key = 10 hours

Keith: 5 1/2 keys x 4 hours/key = 22 hours

Sidra: 3 keys x 4 hours/key = 12 hours

Total hours of homework per month:

= 20 + 10 + 22 + 12

= 64 hours.

Read more about hours

brainly.com/question/302808

#SPJ1