helen spent $7.75 to purchase 23 snacks for the club meeting. chips are
A school psychologist notes that the average number of times that students are disruptive during class is 1.4 [μ=1.4] times per day. Following recent classroom policy changes, the psychologist tests if the number of disruptions during class has changed. He records the following number of disruptions observed during a class day: 2, 4, 3, 5, 1, 1, and 4.
A. Test the hypothesis that the number of complaints has increased or decreased using a .05 level of significance.
B. Compute effect size using estimated Cohen's d.
Answer:
Reject the Null ;
0.928
Step-by-step explanation:
Given the data: 2, 4, 3, 5, 1, 1, 4
Sample mean = (2 + 4 + 3 + 5 + 1 + 1 + 4) / 7 = 2.857
Standard deviation, s = 1.57 ( using calculator)
The hypothesis :
H0 : μ = 1.4
H1 : μ ≠ 1.4
Since sample size is small, use T test
Test statistic :
Tstatistic = (x - μ) / s/sqrt(n)
Tstatistic = (2.857 - 1.4) / 1.57/sqrt(7)
Tstatistic = 1.457 / 0.593 = 2.455
Two tailed test at α = 0.05
Tcritical at df = 7-1 = 6 ; α = 0.05 = 2.447
Tstatistic > Tcritical ; reject the null
Since ;
2.455 > 2.447 ; we reject the null ;
There is significam evidence that Number of complaints has changed.
Effect size ;
d = (x - μ) / s
d = (2.857 - 1.4) / 1.57
d = 1.457 / 1.57
d = 0.928
Suppose you have just poured a cup of freshly brewed coffee with temperature 90∘C in a room where the temperature is 20∘C.
Newton's Law of Cooling states that the rate of cooling of an object is proportional to the temperature difference between the object and its surroundings. Therefore, the temperature of the coffee, T(t), satisfies the differential equation
dT/dt=k(T−Troom)
where Troom=20 is the room temperature, and k is some constant.
Suppose it is known that the coffee cools at a rate of 1∘C per minute when its temperature is 70∘C.
A. What is the limiting value of the temperature of the coffee?
limt→[infinity]T(t)= ________
B. What is the limiting value of the rate of cooling?
limt→[infinity]dT/dt= _________
C. Find the constant k in the differential equation.
k= _________
D. Use Euler's method with step size h=2 minutes to estimate the temperature of the coffee after 10 minutes.
T(10)= _________
Solution :
A). As the time passes the temperature of the coffee tends to acquire the temperature of the room, so the limiting value of the temperature of the coffee is 20°C. i.e.
[tex]$\lim_{t \to \infty} T(t)=20$[/tex]
B). And limiting value of rate of cooling is given by :
[tex]$\lim_{t \to \infty} \ \frac{dT}{dt} =\lim_{t \to \infty} \ [k(T-T_{room})] $[/tex]
[tex]$=k . \lim_{t \to \infty} (T-T_{room})$[/tex]
[tex]$=k .[ \lim_{t \to \infty} T-\lim_{t \to \infty} T_{room}]$[/tex]
[tex]$=k.[T_{room}-T_{room}]$[/tex]
= k. 0
= 0
C). Given, [tex]$\frac{dT}{dt} = -1, $[/tex] when T(t) = 70° using this in the given equation,
-1 = k.(70-20)
k = -0.02
D). By Euler method, we get
[tex]$T_{n+1}=T_n + h \ f(t_n, T_n)$[/tex]
[tex]$t_{n+1}=t_n +h$[/tex]
where, [tex]$f(t,T) =k(T-T_{room})$[/tex]
= -0.02(T - 20)
We have [tex]$T_0 = 90^\circ$[/tex] at t = 0 and h = 2.
So [tex]$t_1 = 0+2 = 2$[/tex]
∴ [tex]$T_1=T_0 + h \ f(t_0,T_0)$[/tex]
= 90+2[-0.02(90-20)]
= 87.2
At [tex]$t_2 = 2+2 = 4$[/tex]
[tex]$T_2=T_1 + h \ f(t_1,T_1)$[/tex]
= 87.2+2[-0.02(87.2-20)]
= 84.51
At [tex]$t_3 = t_2+2 = 4+2=6$[/tex]
[tex]$T_3=T_2 + h \ f(t_2,T_2)$[/tex]
= 84.51+2[-0.02(84.51-20)]
= 81.93
At [tex]$t_4 = t_3+4 = 6+2=8$[/tex]
[tex]$T_4=T_3 + h \ f(t_4,T_4)$[/tex]
= 81.93+2[-0.02(81.93-20)]
= 79.45
At [tex]$t_5 = t_4+2 = 8+2=10$[/tex]
[tex]$T_5=T_4 + h \ f(t_4,T_4)$[/tex]
= 79.45+2[-0.02(79.45-20)]
= 77.07
So after 10 minutes, the temperature of the coffee will be 77.07°C.
Hurry I need help
142 is what percent of 596?
(Write your answer as a percent rounded to the nearest tenth of a percent. Include the % on your answer.)
Answer:
Step-by-step explanation:
142/596 ≅ 0.238 = 23.8%
[tex] \frac{142}{596} \times 100[/tex]
= 23.8255....
= 23.8%
Which line plot displays a data set with an outlier?
Answer:
The third plot shows the outlier
Step-by-step explanation:
The other plots dots are closer together than the third image. Therefore making the image that has the outlier would be the third image represented
Find tan0 where 0 is the angle shown
PLEASE I NEED HELP
Answer:
tan = 12/5..............
HELPPP I NEED THIS BY 2:30
You bought a book for $5 and four bookmarkers. You spent a total of $13. How much did each bookmarker
cost?
*show work*
Answer:
they each costed $2
Step-by-step explanation:
all you do is take 5 and count how many fingers u have left then u get 2
Answer:
Each book mark is 2 dollars
Step-by-step explanation:
You subtract the $5 from the $13 and that is equal to 8 dollars. Then you divide 8 by the 4 bookmarks and the answer is 2 dollars.
Jenna's class brought in 40 pieces of fruit for a celebration and 32 pieces of fruit were eaten. What percentage of the fruit was NOT eaten?
Answer:
20%
Step-by-step explanation:
40 pieces total
32 pieces eaten
40 - 32 = 8
8 pieces not eaten
Percentage = (part / whole) x 100%
Percentage = (8 / 40) x 100% = 0.2 x 100%
Percentage = 20%
PLEASE HELP !! ILL GIVE BRAINLIEST *EXTRA POINTS*..
IM GIVING 40 POINTS !! DONT SKIP :((.
Answer:
Step-by-step explanation:
(5, -30) (6, -36)
(-36 + 30)/(6 - 5) = -6/1 = -6
y + 30 = -6(x - 5)
y + 30 = -6x + 30
y = -6x + 0
y = -6x
The Sunny Days Apartment building has a cylindrical, above ground pool in the yard. The radius of the pool is 2 times its height, and the volume is 3000 cubic feet. How deep is the pool? In other words, what is the height of the pool?
9514 1404 393
Answer:
6.2 ft
Step-by-step explanation:
The volume of a cylinder is given by ...
V = πr²h
Here, we have r=2h and V=3000 ft³. Putting these numbers into the formula and solving for h, we get ...
3000 ft³ = π(2h)²h
(3000 ft³)/(4π) = h³ . . . . . divide by the coefficient of h³
h = ∛(750/π) ft ≈ 6.2 ft
The pool is about 6.2 feet deep.
The radius of a parachute is shown below.
What is the diameter of the parachute? What is the circumference of the parachute?
Step-by-step explanation:
Diameter is 6 ft
3 ft + 3ft
Resuelve la siguiente operación (3/4+1/2):(5/3+1/6)
Answer: 0.6818182
Step-by-step explanation:
Answer:
fhduogherogi
Step-by-step explanation:
PLEASE HELP !! ILL GIVE BRAINLIEST *EXTRA POINTS*..
IM GIVING 40 POINTS !! DONT SKIP :((.
Answer:
you add 1 to 5 and then you find y but on x you multiple t
how do I solve this factoring problem?
The perimeter of a rectangle is 180 cm. The length is 3 times more than the width. What
is the length of the rectangle
Answer:
67.5,
Step-by-step explanation:
22.5x3 =67.5, P=2(l+w)=2·(22.5+67.5)=180
Jeff Bezos, who owns Amazon, has a net worth of approximately $143.1 billion (as of mid-2018). An employee in the Amazon distribution center earns about $13 an hour. The estimated lifespan of the employee is 71 years. If the employee worked 24 hours a day, every day of the year from the moment of his birth, how many lifespans would it take for him to earn wages equivalent to Jeff Bezos' net worth? Round the answer to the nearest whole number.
Answer:
Lifetimes=17,698.39
Step-by-step explanation:
The number of hours, H, in the employee's lifetime is
H=24(365)(71)=621960
At 13/hour, this is lifetime wages of
13(621960)=8,085,480
Divide this into 143,100,000,000 to get
Lifetimes=17,698.39
Note that this does NOT imply that the employee is underpaid.
Simply the expression by combining the like terms:
-6j + 4 + 2j - 1
Answer:
-4j + 3 or 3 - 4j
Step-by-step explanation:
you can combine the terms in any order that you want, but i'm going to begin with the j terms.
first, identify the like terms.
-6j + 4 + 2j - 1
then combine the like terms.
-6j + 2j = -4j
now identify the next set of like terms.
-6j + 4 + 2j - 1
combine those like terms.
4 - 1 = 3
after combining the first set of like terms, you're left with: -4j
after combining the second set of like terms, you're left with: 3
therefore the simplified expression is -4j + 3 or 3 - 4j. rearranging those terms doesn't change the answer, so it doesn't matter what order you write it in.
i hope this helps!! have a great rest of your day :)
1. Use the method described in the activity to find the rational zeros for
-10x3 + 15x+ 16x-12.
Answer:
-42+31x
Step-by-step explanation:
-30+31x-12
-42+31x
ORDER OF OPERATIONS
14 + 28 ÷ 4 − 2*4=
(64 + 6) ÷ 5 − 3*2=
(27 − 7) ÷ 2*2 =
5*2 × (20 ÷ 5) =
Answer:
pmdas perenthisis multiply divide add subtract
Step-by-step explanation:
Answer: 1. 13
2. 8
3. 20
4. 40
Step-by-step explanation:
ignore the green line
Answer:
What are the answer choices? please post it I really want to help
Step-by-step explanation:
Answer:
I don't get this but it might be -12 for K and -3 for I and -6 for J
Step-by-step explanation:
Can anyone save my life and help me with these 2 questions:(
Help on this will mark brainalist!
Answer:
y = 2x - 10
Step-by-step explanation:
Slope-intercept form is...
y = mx + b
To get the slope, you have to use the formula...
(y2 - y1) / (x2 - x1)
In this case,
y2 = 2
y1 = 10
x2 = 6
x1 = 10
So...
(2 - 10) / (6 - 10)
= -8 / -4 = 2
Therefore, slope is 2
y = 2x + b
Using any of the two x and y value provided, input the values in the equation
(I'm going to use 6,2)
2 = 2(6) + b
2 = 12 + b
b = -12 + 2
b = -10
Put this all together...
y = 2x - 10
Hope this helps :)
Let me know if there are any mistakes!!
Domain answers:
-The set of all real numbers from 0-60
-The set of all real numbers from 500-2000
-The set of all real numbers from 25-500
-{0,1,2,3...,500}
-{25,50,75,100,...}
-{60,61,62,63,...,2000}
Range answers:
The set of all real numbers from 0-60
-The set of all real numbers from 500-2000
-The set of all real numbers from 25-500
-{0,1,2,3...,500}
-{25,50,75,100,...}
-{60,61,62,63,...,2000}
Domain= "number of minutes water has been added" and the set of all real numbers would be from 0-60
Range= "amount of water in the pond(in liters) and the set of all real numbers from 500-2000
I hope this helps
I'm terribly sorry if this is wrong
4% of what number is 39
Answer:
975
Step-by-step explanation:
39 ÷ 4% = 975
Answer:
975Step-by-step explanation:
Formula = Number × 100 = 39 × 100
Percent 4
Following shows the steps on how to derive this formula
Step 1 : if 4% of a number is 39, then what is 100% of the number ? Setup the equation.
39 = Y
4% 100 %
Step 2 : Solve for Y
Using cross multiplication of two fractions , we get
4Y = 39 × 100
4Y = 3900 = 975
100
In the figure, △XYZ ≅ △MNL.
Find m∠Z.
Answer:
m∠Z= 23°
Step-by-step explanation:
if they're equal, as are their angles
124°+33°= 157°
180°-157°= 23°
m∠Z = 23°
The triangles are congruent. Therefore,
ΔXYZ ≅ ΔMNL
∠Y ≅ ∠N
Therefore,
∠Y = 124°
Sum of angles in a triangle = 180°
33 + 124 + m∠Z = 180°
157 + m∠Z = 180°
m∠Z = 180 - 157
m∠Z = 23°
Read more here: https://brainly.com/question/22834723?referrer=searchResults
I need a answer right now I’ll give you points!
Answer:
G. 118⁰100% right answer
Answer:
G. 118°
Step-by-step explanation:
Imagine a line, parallel to AD, that passes through B to a point x on the line CD.
∠CBX=∠CAD=28 (corresponding angles)
∠EBX=90 (BX║ED, BE║XD)
∠CBE=∠CBX+EBX
∠CBE=28+90
∠CBE=118°
There are 23 bears in Yellow Park. There are 5 times as many bears in Green Park. Which equation will help us find out how many bears are in Green Park?
A. b=23+5
B. b=23*5
C. b=23/5
D. b=23-5
Answer:
B
Step-by-step explanation:
"5 times as many bears"
A would be 5 more bears than,
B would be 5 times more bears than,
C would be 5 times less bears than, and
D would be 5 less bears than.
Answer:
B. b = 23 * 5
Step-by-step explanation:
Yellow Park: 23 bears
Green Park: 5 times as many bears as in Yellow Park
5 times 23 bears is is 5 * 23 or 23 * 5
Answer: B. b = 23 * 5
PLZ help i do know the answer to this already from another brainly question but i just would like to understand how its solved so please help. This figure consists of a rectangle and a quarter circle.
What is the perimeter of this figure?
Use 3.14 for π.
Enter your answer as a decimal in the box.
Answer:
66.56 cmStep-by-step explanation:
The figure consist of:
1. A rectangle with sides 10 cm and 17 cm2. A quarter circleThe perimeter is:
P = 1/4C + 2*10 + 17 + (17 - 8) + 8 P = 1/4*2*3.14*8 + 54 = 66.56 cmThe sum of three numbers is 123. The second number is 8 more than the first. The third number is 3 times the first. What are the numbers ?
First number: 23
Second number: 31
Third number: 69
Answer:
That is correct
Step-by-step explanation:
if you add all those numbers together, it will add up to 123... i think
In your own words describe the relationship between wave frequency and the energy of the wave!!! YOUR OWN WORDS please
*＊✿❀ ❀✿＊**＊✿❀ ❀✿＊**＊✿❀ ❀✿＊**＊✿❀ ❀✿＊**＊✿❀ ❀✿＊*
Answer:
Hey! :)
Step-by-step explanation:
You could create a wave with a higher frequency on a rope by wiggling up and down at a faster rate, the wave should become shorter. Clearly you will find a relationship between wave length and frequency :)
＊✿❀ ❀✿＊**＊✿❀ ❀✿＊**＊✿❀ ❀✿＊**＊✿❀ ❀✿＊**＊✿❀ ❀✿＊*
Have a nice day! :)