A sample of 25 undergraduates reported the following dollar amounts of entertainment expenses last year:

769 691 699 730 711 765 702 718 719 712 768 688 757 695 768 735 709 758 708 693 736 700 687 772 715

Required:
a. What are the range and standard deviation?
b. Use the Empirical Rule to establish an interval which includes about 95 percent of the observations.

Answers

Answer 1

Answer:

[tex]Range = 85[/tex]

[tex]\sigma = 28.71[/tex]

[tex]Interval = [666.78, 781.62][/tex]

Step-by-step explanation:

Given

The data for 25 undergraduates

Solving (a): Range and Standard deviation

The range is:

[tex]Range = Highest - Least[/tex]

From the dataset:

[tex]Highest = 772[/tex]

[tex]Least = 687[/tex]

So:

[tex]Range = Highest - Least[/tex]

[tex]Range = 772-687[/tex]

[tex]Range = 85[/tex]

The standard deviation is:

[tex]\sigma = \sqrt{\frac{\sum(x - \bar x)^2}{n}}[/tex]

First, calculate the mean

[tex]\bar x = \frac{769 +691 +............+715}{25}[/tex]

[tex]\bar x = \frac{18105}{25}[/tex]

[tex]\bar x = 724.2[/tex]

So, the standard deviation is:

[tex]\sigma = \sqrt{\frac{(769-724.2)^2 +(691-724.2)^2 +(699-724.2)^2 +(730-724.2)^2 +............+(715-724.2)^2}{25}}[/tex]

[tex]\sigma = \sqrt{\frac{20604}{25}}[/tex]

[tex]\sigma = \sqrt{824.16}[/tex]

[tex]\sigma = 28.71[/tex]

Solving (b): The interval of the 95% of the observation.

Using the emperical rule, we have:

[tex]Interval = [\bar x - 2*\sigma, \bar x+ 2*\sigma][/tex]

[tex]Interval = [724.2 - 2*28.71, 724.2 + 2*28.71][/tex]

[tex]Interval = [666.78, 781.62][/tex]


Related Questions

help please jfisaljfdlsajflsd

Answers

9514 1404 393

Answer:

  108 square units

Step-by-step explanation:

The area of a trapezoid is given by the formula ...

  A = 1/2(b1 +b2)h

This trapezoid has bases 8 and 1, and a height of 24. Its area is ...

  A = (1/2)(8 +1)(24) = 108 . . . square units

find the derivative
f (x ) = (x-5)^2 (3-x)^2​

Answers

Given:

The function is

[tex]f(x)=(x-5)^2(3-x)^2[/tex]

To find:

The derivative of the given function.

Solution:

Chain rule of differentiation:

[tex][f(g(x))]'=f'(g(x))g'(x)[/tex]

Product rule of differentiation:

[tex][f(x)g(x)]'=f(x)g'(x)+g(x)f'(x)[/tex]

We have,

[tex]f(x)=(x-5)^2(3-x)^2[/tex]

Differentiate with respect to x.

[tex]f'(x)=(x-5)^2\dfrac{d}{dx}(3-x)^2+(3-x)^2\dfrac{d}{dx}(x-5)^2[/tex]

[tex]f'(x)=(x-5)^2[2(3-x)(0-1)]+(3-x)^2[2(x-5)(1-0)][/tex]

[tex]f'(x)=(x^2-10x+25)(-6+2x)+(9-6x+x^2)(2x-10)[/tex]

[tex]f'(x)=(x^2)(-6)+(-10x)(-6)+(25)(-6)+(x^2)(2x)-10x(2x)+25(2x)+(9)(2x)+(-6x)(2x)+x^2(2x)+9(-10)+(-6x)(-10)+x^2(-10)[/tex]

On further simplification, we get

[tex]f'(x)=-6x^2+60x-150+2x^3-20x^2+50x+18x-12x^2+2x^3-90+60x-10x^2[/tex]

[tex]f'(x)=(2x^3+2x^3)+(-6x^2-20x^2-12x^2-10x^2)+(60x+50x+18x+60x)+(-90-150)[/tex]

[tex]f'(x)=4x^3-48x^2+188x-240[/tex]

Therefore, the derivative of the given function is [tex]f'(x)=4x^3-48x^2+188x-240[/tex].

Tamara uses a coupon to save 20% off her purchase at the bookstore. The original cost of Tamara's purchase is d dollars.
Which expressions represent the cost, in dollars, of Tamara's purchase after using the coupon? Choose all that apply.

Answers

Answer:

The equation would be d - (d×0.2)

Find y if the distance between
points P and R is 25 and point R
is located in the first quadrant.
p= (3,-18) r=(10,y)

Answers

Answer:

y = 6

Step-by-step explanation:

[tex]\sqrt{(10-3)^2 + (y+18)^2} = 25 \\ 49 + y^2 + 324 + 36y = 625 \\[/tex]

y^2 + 36y - 252 = 0

(y-6)(y+42) = 0

y = 6 (accettable)

y = -42 (not accettable)

usain bolt broke the world record for the mens 100 m sprint with a time of 9.58 seconds. Florence Griffith Joyner broke the world record for the womens 100 m sprint with a time of 10.49 seconds. If florence and usain were running at their world-record speed in the same race, how many metres behind usain would florence finish?

Answers

Answer:

If Florence Griffith Joyner and Usain Bolt were running at their world-record speed in the same race, Florence Griffith Joyner would finish 8.67 m behind Usain Bolt.

Step-by-step explanation:

Step 1: Determine the speed of each athlete in m/s

Speed = distance / time

Distance = 100 m

Usain Bolt's speed: 100m / 9.58 s = 10.438 m/s

Florence Griffith Joyner's speed: 100 m/ 10.49 s = 9.533 m/s

Step 2: Determine the distance covered by Florence Griffith Joyner in 9.58 s

Distance = Speed × time

Distance covered by Florence Griffith Joyner = 100 m/ 10.49 s × 9.58 s = 91.32 m

Step 3: Determine the difference in the distance covered by Usain Bolt and Florence Griffith Joyner after 9.58 s

After 9.58 s, Usain Bolt have covered a distance of 100 m

After 9.58 s, Florence Griffith Joyner have covered a distance of 91.33 m

Difference between the distances = (100 - 91.33) m = 8.67 m

Therefore, if Florence Griffith Joyner and Usain Bolt were running at their world-record speed in the same race, Florence Griffith Joyner would finish 8.67 m behind Usain Bolt

What angle is formed by the arms of a clock when the time is 6:50 a.m

Answers

the angel would be 95°
x=300°-(180°+24.99999)
300-204.99999
then round
so 95°

A group of students were asked if they carry a credit card. The responses are listed in the table.


If a student is selected at random, find the probability that he or she owns a credit card given that the student is a freshman. Round your answer to three decimal places.

Answers

Answer:

0.383 (3 d.p.)

Step-by-step explanation:

Probability formula

[tex]\sf Probability\:of\:an\:event\:occurring = \dfrac{Number\:of\:ways\:it\:can\:occur}{Total\:number\:of\:possible\:outcomes}[/tex]

Let P(A) = probability that the student owns a credit card

Let P(B) = probability that the student is a freshman

Use the given table to calculate the probability that the student is a freshman and owns a credit card:

[tex]\implies \sf P(B \cap A)=\dfrac{23}{100}=0.23[/tex]

Use the given table to calculate the probability that the student is a freshman:

[tex]\sf \implies P(B) = \dfrac{60}{100}=0.6[/tex]

To find the probability that the student owns a credit card given that they are a freshman, use the conditional probability formula:

Conditional Probability Formula

The probability of A given B is:

[tex]\sf P(A|B)=\dfrac{P(B \cap A)}{P(B)}[/tex]

Substitute the found values into the formula:

[tex]\implies \sf P(A|B)=\dfrac{0.23}{0.6}=0.383333...[/tex]

Therefore, the probability that the student owns a credit card given that they are a freshman is 0.383 (3 d.p.).

P(Freshman credit card holder)

23/1000.23

P(Freshman)

60/1000.60

P(Freshman credit holder|Freshman)

0.23/0.60.383

The correlation coefficient for practicing violin and getting better grades in a group of people is 0.8. Analyze the following statement:

Playing violin causes students to get better grades.

Is this a reasonable conclusion?

Answers

Answer:

D No; even though there is a strong positive correlation, playing violin doesn't cause students to get better grades

HELP!! PLEASE ASAP!!!!

Answers

A is the correct answer

Wylie is renting a bicycle from a local shop that charges $5 to rent a helmet, plus an hourly rate of $8.50 for the bike. For how long can Wylie rent a bicycle if he pays a total of $47.50? Enter your answer in the box.
hours

Answers

Answer:

Wylie can rent a bike for 5 hours.

Step-by-step explanation:

Since Wylie is renting a bicycle from a local shop that charges $ 5 to rent a helmet, plus an hourly rate of $ 8.50 for the bike, to determine for how long can Wylie rent a bicycle if he pays a total of $ 47.50 the following calculation has to be done:

(47.50 - 5) / 8.50 = X

42.50 / 8.50 = X

5 = X

Therefore, Wylie can rent a bike for 5 hours.

HELP ME PLEASE!!!!!
The 2 questions is down below with the picture; please let me know.

Answers

Given:

1. 60 is the sum of 15 and Mabel's age.

2. Given equation is

[tex]-8(x+1)=-40[/tex]

To find:

1. The equation for the given situation.

2. Complete the two column proof.

Solution:

1.

60 is the sum of 15 and Mabel's age.

Let m be the Mabel's age. Then,

[tex]15+m=60[/tex]

Therefore, the required equation for the given situation is [tex]15+m=60[/tex].

2.

The complete two column proof is:

        Steps                                            Reasons

[tex]-8(x+1)=-40[/tex]                                   Given equation

[tex]\dfrac{-8(x+1)}{-8}=\dfrac{-40}{-8}[/tex]                                  Division Property of Equality

[tex]x+1=5[/tex]                                               Simplifying

[tex]x+1-1=5-1[/tex]                                   Subtraction Property of Equality

[tex]x=4[/tex]                                                     Simplifying

Which pair of diagrams best models the equation 3/4 = 6/8.

Answers

the one we barely see in the photo you took seems a good fit. on the left wich 3 blue stripes and one white. and with stripes of half the size, 6 blue and two white

Answer:

Answer is a because it has

Step-by-step explanation:

3 blue and 6 blue trust me

Find the distance between the points ( 19,-5) and ( 11, 10).

Answers

Answer:

Let the given two points be A & B. Let A ( 19 , - 5 ) be ( x₁ , y₁ ) & B ( 11 , 10 ) be ( x₂ , y₂ )

Remember : The formula to find out the distance between any two points is [tex] \tt{ \sqrt{( x_{2} -x _{1}) ^{2} + (y _{2} - y_{1}) ^{2} }} [/tex] .

[tex] \large{ \tt{✺ \: SOLUTION}} : [/tex]

[tex] \large{ \boxed{ \tt{AB = \sqrt{(x_{2} - x_{1}  ) ^{2} + (y_{2} - y_{1}) ^{2}   } }}}[/tex]

[tex] \large{ \tt{⟶ \sqrt{(11 - 19)^{2} + (10 - ( - 5) ^{2} } }}[/tex]

[tex] \large{ \tt{⟶ \sqrt{ {8}^{2} + {15}^{2} } }}[/tex]

[tex] \large{ \tt{⟶ \: \sqrt{64 + 225} }}[/tex]

[tex] \large{ \tt{⟶ \sqrt{289}}} [/tex]

[tex] \boxed{ \large{ \tt{⟶ \: 17 \: \text{units}}}}[/tex]

And we're done! Let me know if you have any questions regarding my answer :)

▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁

Select the correct answer.
What is the factored form of this expression?
-12x+36
ОА.(x - 12)(x-3)
O B. (x - 6)^2
OC. (x + 6)^2
OD. (x-6)(x+6)

Answers

The answer is B

the method use to solved this is called foil

In right triangle PQR, the length of side P Q is 70, the measure of angle P is 90 degrees, and the measure of angle R is 38 degrees. How we will represents the length of side QR?

Answers

Answer:

70/sin38°

Step-by-step explanation:

According to question,we have

PQ=70 ,  ∠P=90° & ∠R=38°

We know, sine rule

So, Sin90° / QR = Sin38° / 70

on solving, we get

QR = 70 / Sin38°

Find f(x) and g(x) so that the function can be described as y = f(g(x)).
y=[tex]\frac{9}{x^2} + 2[/tex]

Answers

Hope this help!!!

Have a nice day!!!

Put the following equation of a line into slope-intercept form, simplifying all
fractions.
12x – 3y = 15

Help plsss

Answers

Answer:

y=4x-5

Step-by-step explanation:

-3y = -12x+15. y = (-12x+15)/(-3). y = (-12x/-3)+(15/-3). y = 4x-5.

1.(06.05 MC)
Albiologist is comparing the growth of a population of flies per week to the number of flies a lizard will consume per week. She has devised an equation to solve for which day (x) the lizard
would be able to eat the entire population. The equation is 2* - 3 = 4x + 2.
Explain to the biologist how she can solve this on a graph using a system of equations. (10 points)

Answers

6x-2 is the correct answer

What is the volume of a cube
of ice with a 3 cm edge?

Answers

Answer:

27 cm

Step-by-step explanation:

every side of a cube is equal to each other. the formula for volume is LxWxH, so 3*3*3=27

4. Damiel and Kianny are going to the Pizza Palace for dinner. Damiel orders 2 slices of pizza and 1 cola and has a bill that totals $12. Kianny orders 3 slices of pizza and 2 colas and has a bill that totals $19.​

Answers

Answer:

if the question is how much does the pizza and coke cost then:

1 slice of pizza is $5 and coke is $2

Step-by-step explanation:

(2×$5)+(1×$2)=$12

(3×$5)+(2×$2)=$19

[tex]Find the missing side or angle of this equation. This is not a right triangle.[/tex]

Answers

Answer:

15.6

Step-by-step explanation:

the angle = 180-61-42=77°

x = 14.sin 77/sin 61

= 14×0.97/0.87

= 15.6

I need help with #7. Please help. I have to show all work so please explain

Answers

Answer: 2√17 A website to use for this would be "M a t h w a y"!!! Good luck, hope I helped!!!

Classify the quadrilateral.

Answers

Answer:

B Kite.

Step-by-step explanation:

It has 2 distinct pairs of equal size.

Answer:

B) kite

Step-by-step explanation:

Kite has two pairs of equal-length adjacent sides

(doesnr let me put 2 pictures) what name length describes the center of the data? (a question to the number line) (i mark brainlist)

Answers

Work it out yourself lad

Answer:

three

Step-by-step explanation:

answer might be 3... shortest name length

in induction, you look for a pattern and then form an educated guess or?

Answers

Answer:

look for a pattern then take an estimate or 'educated guess'

Step-by-step explanation:

Answer:

The answer is conjugation

Hope this helps!

What is the surface area of the solid that this net can form?
8 mm
25 mm
8 mm
5 mm
5 mm
8 mm
8 mm
5 mm
5 mm
8 mm
8 mm
25 mm
O 730 square millimeters
O 875 square millimeters
O 1,000 square millimeters
O 1,444 square millimeters

Answers

Answer:

730

Step-by-step explanation:

separate each rectangle

use the formula to calculate the area of each rectangle.

1st rectangle

area = length ×breadth

length =5, breadth =8+25+8=41

A1=5×41=205

2nd rectangle

A2=8×25=200

....

A3=5×25=125

A4=8×25=200

Add all As and you have your ans 730

Andrew walks 2000 feet from his house to his office. What distance does he cover?
A. 18,000 in.
B. 24,000 in.
C. 25,000 in.
D. 30,000 in.

Answers

The answer is B. 24,000 in.

What is the value of x?
O 20
(x + 40)
(3x)
R
O 35
w
O 60
S
070

Answers

Answer:

Hello! answer: 20

Step-by-step explanation:

These are vertical angles meaning they will have the same measure so... 20 + 40 = 60 20 × 3 = 60 therefore x = 20 hope that helps!

In the given scenario, the value of x is 20. The correct option is A.

What is parallelogram?

A parallelogram is a quadrilateral with two pairs of parallel sides. This means that opposite sides of a parallelogram are parallel and congruent, and opposite angles are congruent as well.

To find the value of x in the given diagram, we need to use the fact that the opposite sides of a parallelogram are equal in length.

Therefore, we can set the expressions for the opposite sides equal to each other and solve for x:

x + 40 = 3x

Simplifying the equation, we get:

40 = 2x

Dividing both sides by 2, we get:

x = 20

Therefore, the value of x is 20.

For more details regarding parallelogram, visit:

https://brainly.com/question/29147156

#SPJ7

The product of a and the sum of a and 34?

Answers

A times 34 idfbutcgnjytfxvhitd

Roderick has an Internet service that charges by the hour. This piecewise function shows the cost of the Internet service based on the number of hours that Roderick uses
the Internet.
when x 34
10
(10 + 2.50(x-4)
when x > 4
Last month, Roderick used the Internet for 7.5 hours. What was he charged?
Helppppp Plssssssss

Answers

Answer:

18.75 is the answer

Step-by-step explanation:

since the internet usage is more than 4 hrs, the second equation will be used. that is

cost = (10 + 2.50 (x - 4)) where x is the usage hours.

thus

[tex]cost = 10 + (2.5 \times (7.5 - 4)) \\ = 10 + (2.5 \times 3.5) \\ = 10 + 8.75 \\ = 18.75[/tex]

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