The price of a 9-minute phone call is $1.35. What is the price of an 11-minute phone call?

Solution :

The test is distributed normally with mean of 72.8 and the standard deviation of 7.3

Finding numerical limits for the D grade.

D grade : Scores below the top 80% and above the bottom 10%.

Let the bottom limit for D grade be [tex]$D_1$[/tex] and the top limit for D grade be [tex]$D_2$[/tex].

First find the bottom numerical limit for a D grade is :

[tex]$P(X<D_1)= 0.10$[/tex]

[tex]$P(X\leq D_1)= 0.10$[/tex]

[tex]$P\left(\frac{X-\mu}{\sigma} \leq \frac{D_1-\mu}{\sigma}\right) = 0.10$[/tex]

[tex]$P\left(Z \leq \frac{D_1-72.8}{7.3}\right) = 0.10$[/tex]    ..........(1)

From (1)

[tex]$\frac{D_1 - 72.8}{7.3} = -1.28$[/tex]

[tex]$D_1 = -1.28(7.3)+72.8$[/tex]

      = 63.45

       ≈ 64

Now the top numerical limit for D grade :

[tex]$P(X>D_2)= 0.80$[/tex]

[tex]$1-P(X\leq D_2)= 0.80$[/tex]

[tex]$P(X\leq D_2)= 1-0.80$[/tex]

[tex]$P(X\leq D_2)= 0.20$[/tex]

[tex]$P\left(\frac{X-\mu}{\sigma} \leq \frac{D_2-\mu}{\sigma}\right) = 0.20$[/tex]

[tex]$P\left(Z \leq \frac{D_2-72.8}{7.3}\right) = 0.20$[/tex]    ..........(2)

From (2)

[tex]$\frac{D_2- 72.8}{7.3} = -0.84$[/tex]

[tex]$D_12= -0.84(7.3)+72.8$[/tex]

      = 66.668

       ≈ 67

Therefore, the numerical limit for a D grade is 64 to 67.

Answer:

7 : 30

Step-by-step explanation:

7/36 : 5/6

42 : 180

7 : 30

Answer:

The best way to measure an angle is to use a protractor. To do this, you'll start by lining up one ray along the 0-degree line on the protractor. Then, line up the vertex with the midpoint of the protractor. Follow the second ray to determine the angle's measurement to the nearest degree.

Answer:

Step-by-step explanation:

Answer:

x = 14

Step-by-step explanation:

Credits = 12  Semesters = 6   Total Credits = 96

6x = 96 - 12

6x = 84

Divide 6x = 84 by 6.

x = 14

[tex]\frac{96 credits-12 credits}{6 semesters} =\frac{84 credits}{6 credits} = \frac{14 credits}{1 semester}[/tex]

Answer:

x = 20

y = 12

Step-by-step explanation:

opposite angles are congruent so we can set up this equation:

5x + 29 = 7x - 11

29 = 2x - 11

40 = 2x

x = 20

5(20) + 29 = 129

7(20) - 11 = 129

3y + 15 = 5y - 9

15 = 2y - 9

24 = 2y

y = 12

3(12) + 15 = 51

5(12) - 9 = 51

Answer:

it will also measure 131 degree

hope it helps

131 degree

Answer: £46.44

Step-by-step explanation:

£56 × 0.86 or (1 - 0.14)

Answer:

the second is correct

Step-by-step explanation:

choose as brainliest

Answer:

x = 1

y = -1

Step-by-step explanation:

-5x + 5y = -10

rewrite the order:

5y = 5x  - 10

6x + 5y = 1

rewrite the order:

5y = 1 - 6x

substitute for 5y:

5x - 10 = 1 - 6x

simplify:

11x = 11

x = 1

5y = 1 - 6(1) = -5

y = -1

Answer:

3 8/9

Can I get Brainliest?

Answer:

3 8/9

Step-by-step explanation:

9 goes into 35 3 times with a remainder of 8

Answer:

He had $200 to begin with.

Answer:

they are congruent because they are corresponding angles

Step-by-step explanation:

So if Joel raced 3 laps , and the total distance is less then 3 miles then it has to be Track C.

Answer:

y cuál es la cantidad inicial de platos?

Answer:

A,CAND D

Step-by-step explanation:

ADD ME AS BRAINLIEST

Answer:

they should all be checked

Step-by-step explanation:

ap3x

Answer:

a) [tex]P_y = \frac{4}{y} * \frac{1}{3}^y * \frac{2}{3}^{4-y}[/tex]

b) 0.033

Step-by-step explanation:

Let Y represents the number of judges preferring a formula.

There are total four judges and each judge can select either A or B

n = 4, p = 1/3

a) The probability function is

[tex]P_y = \frac{4}{y} * \frac{1}{3}^y * \frac{2}{3}^{4-y}[/tex]

b)

Substituting the value of y -3 in above equation, we get -

[tex]P_3 = \frac{4}{3} * \frac{1}{3}^3 * \frac{2}{3}^{4-3}\\= \frac{4}{3} * 0.037 * 0.67\\= 0.033[/tex]

Answer:

Rule 1. Adding/subtracting the same number on both sides.

   Example: The inequality x-2>5 has the same answer as the inequality x > 7.

Rule 2. Switching sides and changing the orientation of the inequality sign.

   Example: The inequality 5-x> 4 has the same solutions as the inequality 4 < 5 - x.

Done ✔

Answer:

y= 2/7

b= 43

Step-by-step explanation:

(x*5)-10=45=equation

im extra so x would be 7

Step-by-step explanation:

uedhhhjdjdhdhdddjjdhvdhddbdbddbb

Answer:

A

Step-by-step explanation:

im not 100 % sure hope i am correct

Answer:

[tex]arclength = 13.44 ft[/tex]

Step-by-step explanation:

We are given PS = 28 feet, which is the length of the diameter.

The formula for arc length is  [tex]2\pi r\frac{x}{360}[/tex], where x is the degrees.

So, we need to find the radius. We know that the radius is half of the diameter, so:

[tex]\frac{28}{2}=14 ft[/tex]

We also need to find ∠TXS. Since we know the diameter is a line that crosses the center point of the circle, we also know that ∠PXT and ∠TXS add up to 180°. So:

∠PXT + ∠TXS = 180

125 + ∠TXS = 180

∠TXS = 180 - 125

∠TXS = 55°

Now, we can use the arc length formula:

[tex]arclength=2\pi r\frac{x}{360}[/tex]

[tex]arclength=2\pi (14)\frac{55}{360}[/tex]

[tex]arclength=13.43903524...[/tex]

[tex]arclength = 13.44 ft[/tex]

Check my work to make sure! Hope this helps!

Answer:

y=-2x+8

Step-by-step explanation:

So I select 2 points:

(0,8) and (4,0)

so then I find the slope.

m = [tex]\frac{8-0}{0-4} \\=\frac{8}{-4} \\=\frac{2}{-1} \\=-2[/tex]

m = -2

Then the b (y-intercept) is 8, so equation is:

y=-2x+8

Hoped I helped ([P.S. I love math!)

Answer:

D

Step-by-step explanation:

When x = 1, y = 5

When x = 3, y = 15

So, using this, find the slope.

(15 - 5) / (3 - 1) = 10 / 2 = 5

For every x, y increases by 5.

So, y = 5x, or D

Answer:

D

Step-by-step explanation:

5x