A manager records the repair cost for 4 randomly selected stereos. A sample mean of $82.64 and standard deviation of $14.32 are subsequently computed. Determine the 90% confidence interval for the mean repair cost for the stereos. Assume the population is approximately normal. Step 1 of 2 : Find the critical value that should be used in constructing the confidence interval. Round your answer to three decimal places.

Answers

Answer 1

Answer:

CI = (70.861 , 94.418)

Step-by-step explanation:

In order to determine the 90% confidence interval you use the following formula (for a population approximately normal):

[tex]CI=(\overline{x}-Z_{\alpha/2}\frac{\sigma}{\sqrt{n}},\overline{x}+Z_{\alpha/2}\frac{\sigma}{\sqrt{n}})[/tex]    (1)

[tex]\overline{x}[/tex]: mean = 82.64

σ: standard deviation = 14.32

n: sample = 4

α: tail area = 1 - 0.9 = 0.1

Z_α/2 = Z_0.05: Z factor =  1.645

You replace these values and you obtain:

[tex]Z_{0.05}(\frac{14.32}{\sqrt{4}})=(1.645)(\frac{14.32}{\sqrt{4}})=11.778[/tex]

The confidence interval will be:

[tex]CI=(82.64-11.778,82.64+11.778)=(70.861,94.418)[/tex]

The 90% confidence interval is (70.861 , 94.418)


Related Questions

For a certain​ drug, the rate of reaction in appropriate units is given by Upper R prime (t )equalsStartFraction 2 Over t plus 1 EndFraction plus StartFraction 1 Over Start Root t plus 1 End Root End Fraction where t is time​ (in hours) after the drug is administered. Find the total reaction to the drug over the following time periods.
a. From t=1 to t=12.
b. From t=12 to t=24

Answers

Answer:

a) 8.13

b) 4.10

Step-by-step explanation:

Given the rate of reaction R'(t) = 2/t+1 + 1/√t+1

In order to get the total reaction R(t) to the drugs at this times, we need to first integrate the given function to get R(t)

On integrating R'(t)

∫ (2/t+1 + 1/√t+1)dt

In integration, k∫f'(x)/f(x) dx = 1/k ln(fx)+C where k is any constant.

∫ (2/t+1 + 1/√t+1)dt

= ∫ (2/t+1)dt+ ∫ (1/√t+1)dt

= 2∫ 1/t+1 dt +∫1/+(t+1)^1/2 dt

= 2ln(t+1) + 2(t+1)^1/2 + C

= 2ln(t+1) + 2√(t+1) + C

a) For total reactions from t = 1 to t = 12

When t = 1

R(1) = 2ln2 + 2√2

≈ 4.21

When t = 12

R(12) = 2ln13 + 2√13

≈ 12.34

R(12) - R(1) ≈ 12.34-4.21

≈ 8.13

Total reactions to the drugs over the period from t = 1 to t= 12 is approx 8.13.

b) For total reactions from t = 12 to t = 24

When t = 12

R(12) = 2ln13 + 2√13

≈ 12.34

When t = 24

R(24) = 2ln25 + 2√25

≈ 16.44

R(12) - R(1) ≈ 16.44-12.34

≈ 4.10

Total reactions to the drugs over the period from t = 12 to t= 24 is approx 4.10

Convert 88 ounces to pounds.
A.0.18 pounds
B.5.5 pounds
C.1408 pounds

Answers

The answer is B. 5.5 pounds

Answer: it is b because 2.5 lbs = 40 oz. then i know that 40 is half of 80 then there is not way it is the 1000 pound choice

Step-by-step explanation:

Please answer number 3 I will give brainliest thank you!

Answers

Answer:

Skewed to right

Step-by-step explanation:

there is no explanation, it just is, just like how 1+1 is 2

Brainleist! as you promised!

Answer:

Yeah no skewed right, like the guy said.

4) If the data below contained an outlier, which coordinate would best represent the outlier?

(MGSE8.SP.1)

100

90

80

70

60

50

Weight

(kgs)

40

30

20

10

0

0

200

250

100 150

Height (cms)

A. (150, 60)

B. (50,20)

C. (200, 100)

D. (250, 80)

Answers

Answer:

D. (250, 80)

Step-by-step explanation:

a) Outliers are values that "lie outside" the other values in a dataset, because their values are "far away" from the main group of data.

b) In this case, the values of A, B, and C have ratios of their coordinates of about 2.5, but the coordinate ratio of D is more than 3.  This makes it to lie far away from the group of data, and therefore an outliner.

c) The Ratios of the Coordinate Values are calculated as follows: A = 2.5 (150/60), B = 2.5 (50/20), C = 2 (200/100), while D = 3.125 (250/80).

4x-2 im confused because i havent done one like this in ages​

Answers

Answer:

2

Step-by-step explanation:

1. Divide by four

2. two of the fours will cancel out leaving you to divide 4 by - 2 which is 2

Each bag of Skittles is supposed to have at least 30 Skittles. A machine that fills bags has a 0.005 probability of under filling a bag. For every thousand bags, what is the standard deviation for the number of bags (out of a thousand) that are under-filled. Assume the Poisson distribution.

Answers

Answer:

The standard deviation for the number of bags that are underfilled is 2.236.

Step-by-step explanation:

In a Poisson distribution, the probability that X represents the number of successes of a random variable is given by the following formula:

[tex]P(X = x) = \frac{e^{-\mu}*\mu^{x}}{(x)!}[/tex]

In which

x is the number of sucesses

e = 2.71828 is the Euler number

[tex]\mu[/tex] is the mean in the given interval. The variance is the same as the mean, which mean that the standard deviation is the square root of the mean.

In this question:

Expected number of underfilled bags in a sample of n bags is:

[tex]\mu = 0.005*n[/tex]

1000 bags, so

[tex]\mu = 0.005*1000 = 5[/tex]

Standard deviation [tex]S = \sqrt{5} = 2.236[/tex]

The standard deviation for the number of bags that are underfilled is 2.236.

Jaleel and Lisa are simplifying the expression 2(x-2) + 2 as shown

Answers

Answer:

Jaleel is correct because 2 (x + 2) = 2x - 4

Step-by-step explanation:

To solve 2 (x - 2) + 2:

2 (x - 2) + 2

Distribute

2x - 4 + 2

Combine like terms

2x - 2

Lisa did not distribute correctly :)

Answer:

D

Step-by-step explanation:

Which expression is a factor of 4q^2r^3s + 8qrs?

Answers

Answer:

: 4qrs • (qr2 + 2)

Step-by-step explanation:

Step by step solution :

Step 1 :

Equation at the end of step 1 :

((22q2 • r3) • s) + 8qrs

Pulling out like terms :

3.1 Pull out like factors :

4q2r3s + 8qrs = 4qrs • (qr2 + 2)

Final result :

4qrs • (qr2 + 2)

I am really soo sorry if the answer is wrong!

A study of consumer smoking habits includes A people in the 18-22 age bracket (B of whom smoke), C people in the 23-30 age bracket (D of whom smoke), and E people in the 31-40 age bracket (F of whom smoke). If one person is randomly selected from this sample, find the probability of getting someone who is age 23-30 or smokes.

Answers

The correct question is:

A study of consumer smoking habits includes 167 people in the 18-22 age bracket (59 of whom smoke), 148 people in the 23-30 age bracket (31 of whom smoke), and 85 people in the 31-40 age bracket (23 of whom smoke). If one person is randomly selected from this sample, find the probability of getting someone who is age 23-30 or smokes

Answer:

The probability of getting someone who is age 23-30 or smokes = 0.575

Step-by-step explanation:

We are given;

Number consumers of age 18 - 22 = 167

Number of consumers of ages 22 - 30 = 148

Number of consumers of ages 31 - 40 = 85

Thus,total number of consumers in the survey = 167 + 148 + 85 = 400

We are also given;

Number consumers of age 18 - 22 who smoke = 59

Number of consumers of ages 22 - 30 who smoke = 31

Number of consumers of ages 31 - 40 who smoke = 23

Total number of people who smoke = 59 + 31 + 23 = 113

Let event A = someone of age 23-30 and event B = someone who smokes. Thus;

P(A) = 148/400

P(B) = 113/400

P(A & B) = 31/400

Now, from addition rule in sets which is given by;

P(A or B) = P (A) + P (B) – P (A and B)

We can now solve the question.

Thus;

P(A or B) = (148/400) + (113/400) - (31/400)

P(A or B) = 230/400 = 0.575

ASAP! GIVING BRAINLIEST! Please read the question THEN answer CORRECTLY! NO guessing. I say no guessing because people usually guess on my questions.

Answers

Answer:

C. [tex]G(x)=\frac{1}{x} -2[/tex]

Step-by-step explanation:

→For the function G(x) to shift downwards 2 units, there must be a 2 being subtracted.

----------------------------------------------------------------------------------------------------

F(x) + c

-Vertical shift and the function is moved c units

-Graph shifts c units up for F(x) + c and c units down for F(x) - c

----------------------------------------------------------------------------------------------------

This means the correct answer is "C. [tex]G(x)=\frac{1}{x} -2[/tex]."

Insurance Underwriters have established that the probability of city experiencing disasters in the next five years is 0.3 for a Tornado, 0.4 for Hurricane, and 0.1 for both Tornado and Hurricane. A) What is the probability of city experiencing only a Tornado in the next five years?B) What is the probability of city experiencing neither a Tornado nor Hurricane in the next five years?

Answers

Answer:

a. 20%

b. 40%

Step-by-step explanation:

We have the following from the statement:

P (T) = 0.3

P (H) = 0.4

P (T n H) = 0.1

Thus:

a. Tornado-only probability would be the probability of a tornado minus the probability of both tornado and hucaran

 P (only T) = P (T) - P (T n H)

replacing:

 P (only T) = 0.3 - 0.1

 P (only T) = 0.2

In other words, the probability that only one tornado will occur is 20%

b. The probability that there is neither of the two would be the complement of the union between both events, that is:

P (T U H) '= 1 - P (T U H)

and the union is equal to:

P (T U H) = P (T) + P (H) - P (T n H)

replacing:

P (T U H) = 0.3 + 0.4 - 0.1

P (T U H) = 0.6

now if replacing in P (T U H) ':

P (T U H) '= 1 - 0.6

P (T U H) '= 0.4

That is to say that the probability that neither of the two happens is 40%

For the given central angle, determine the distance traveled along the unit circle from the point (1, 0). 210 degrees a. 3.67 units c. 1.83 units b. 1.17 units clockwise d. 7.33 units

Answers

Answer:

3.67 units

Step-by-step explanation:

The central angle is at the point (0,0).

Then it's at the point (1,0)

Then it moved 210 degrees.

Let's bear in mind that we start moving the degree from it's current position.

So moving 210 degrees is moving 180 degrees plus 30 degrees.

Moving 180 degrees I like transforming linearly.

Now the location is at (-1,0)

But the distance covered will be

= 2πr*210/360

r = 1

= 2*3.142*1*(210/360)

= 6.144*0.5833333

= 3.67 units

A hotel rents 220 rooms at a rate of $ 40 per day. For each $ 1 increase in the rate, two fewer rooms are rented. Find the room rate that maximizes daily revenue. The rate that maximizes revenue is $ .

Answers

Answer:

The rooms should be rented at $75 per day for a maximum income of $11250 per day.

Step-by-step explanation:

If the daily rental is increased by $ x

then

Rental:  R (x )=( 40 + x )  dollars per room-day

Number of rooms rented:  N ( x ) = ( 220 − 2 x )  and

Income:  I ( x ) = ( 40 + x ) ( 220 − 2 x ) =8800+140x-2x²  dollars/day

The maximum will be achieved when the derivative of  I ( x )  is zero.

[tex]\frac{dI(x)}{dx} =140-4x=0[/tex]

x=35

so, ($40+$35)=75$per day

 I ( x35) =8800+140(35)-2(35)²= 11250

Which of the following is a subset of every set? * 1)Universal Set 2)Null Set 3)Both of these 4)None of these

Answers

Answer:

[tex]1[/tex]

Step-by-step explanation:

Universal set contains all elements and of which all other sets are subsets.

Goodlife charges its members $30 per month for a gym membership. They currently have 75 clients.
Research has shown that for every $2 increase in their membership price they will lose 3 clients. If they want to maximize their revenue, how much should Goodlife charge per membership? What will their maximized revenue be?

Answers

They should charge $40 per membership, and they will make a maximum revenue of $2400

Do the measures of center make​ sense? A. Only the mode makes sense since the data is nominal. B. All the measures of center make sense since the data is numerical. C. Only the​ mean, median, and midrange make sense since the data is nominal. D. Only the​ mean, median, and mode make sense since the data is numerical.

Answers

Answer:

A. Only the mode makes sense since the data is nominal.

Step-by-step explanation:

Hello!

The objective of the study was to determine if deficiency of carbon dioxide in the soil affects the phenotype of peas.

The variable of study is X: Phenotype of a pea grown in soil with carbon dioxide deficiency.

Possible values of Phenotype codes:

1= smooth-yellow

2= smooth-green

3= wrinkled-yellow

4= wrinkled-green

The absolute frequencies for each phenotype are:

f(1)= 3

f(2)= 4

f(3)= 6

f(4)= 1

n= 14

a) Mean:

X[bar]= (∑xifi)/n= [(1*3)+(2*4)+(3*6)+(4*1)]/14= 33/14= 2.357= 2.36

The average value is always within range of definition of the variable but it does not necessarily correspond to an observation.

b) Median:

To determine the value that corresponds to the median you have to calculate its position:

For even samples the position is:

PosMe= n/2= 14/2= 7

Then you have to arrange the data from least to greatest, in this case, starting from the first category, you have to determine where the seventh observation is within the observed absolute frequencies. The phenotype that corresponds to the 7th observation is 2= smooth-green.

Me= 2= smooth-green.

c) Mode:

The mode corresponds to the most observed category/ value of the variable, i.e. the category with the most observations is 3= wrinkled-yellow

Md= 3= wrinkled-yellow

d) Midrange: (1 + 4)/2= 2.5

e)

As you can see the variable is qualitative and categorical. Even if all central tendency measurements can be calculated, truth is that the only one that shows any valuable information regarding the data set is the mode.

I hope this helps!

If the general term of a sequence is 4, then the sequence is
A)4,4,4,4,
B)4,16,64.216
C)4, 8, 12, 16,

Answers

Answer:

Correct answer is A) 4,4,4,4

Can someone please help me I’m stuck I don’t know

Answers

Answer:

140

Step-by-step explanation:

Because the lines are parallel:

[tex]\dfrac{DE}{35}=\dfrac{60}{15} \\\\DE=4\cdot 35=140[/tex]

Hope this helps!

A motorboat can maintain a constant speed of 13 miles per hour relative to the water. The boat makes a trip upstream to a certain point in 63 ​minutes; the return trip takes 15 minutes. What is the speed of the​ current?

Answers

Answer:

  8 mph

Step-by-step explanation:

The speed in each direction is the speed of the boat with the speed of the current appropriately added. If x is the speed of the current, the upstream speed is 13-x; the downstream speed is 13+x.

The ratio of times is inversely proportional to the ratio of speeds, so we ahve ...

  15/63 = 5/21 = (13-x)/(13+x)

  5(13 +x) = 21(13 -x) . . . . . . . cross multiply

  26x = 13(21 -5) = 13·16

  x = 13·16/26 = 16/2 = 8

The speed of the current is 8 miles per hour.

Which of the following is the slope of the line that passes through the points (-3,5) and (-3,-2)

Answers

Answer:

undefined.

Step-by-step explanation:

-2-5/-3-(-3)

-7/0

Undefined

Find the volume of the cone below.

Answers

Answer:

[tex] V =\frac{1}{3} \pi r^2 h[/tex]

For this case we know that the radius is r=7cm and the height is h =11cm. And replacing we got:

[tex] V=\frac{1}{3} \pi (7cm)^2 (11cm)= \frac{1}{3} \pi (49cm^2) (11 cm)=\frac{539}{3} \pi cm^3[/tex]

And the best option would be:

[tex] V = \frac{539}{3} \pi cm^3 [/tex]

Step-by-step explanation:

For this case we know that the volume of the cone is given by:

[tex] V =\frac{1}{3} \pi r^2 h[/tex]

For this case we know that the radius is r=7cm and the height is h =11cm. And replacing we got:

[tex] V=\frac{1}{3} \pi (7cm)^2 (11cm)= \frac{1}{3} \pi (49cm^2) (11 cm)=\frac{539}{3} \pi cm^3[/tex]

And the best option would be:

[tex] V = \frac{539}{3} \pi cm^3 [/tex]

what is Associative propert

Answers

Answer:

Associative property of multiplication is the grouping of numbers being multiplied can be changed without affecting the product.

here is an example!

Addison Rae work using the associative property:

(-8.5)(5)(-4) =

(-8.5)(-20) =

170

hope this helped it was from my FLVS schooling :)

Three spinners numbered 1 through 12 are spun. What is the probability of spinning a five on the first spinner, an even number on the second spinner, and a multiple of 4 on the third spinner?

1/96
1/72
7/12
5/6

Answers

Answer:

[tex]\frac{1}{96}[/tex]

Step-by-step explanation:

Spinning a 5 is [tex]\frac{1}{12}[/tex]

Spinning even is [tex]\frac{1}{2}[/tex]

Spinning multiple of 4 is [tex]\frac{1}{4}[/tex]

[tex]\frac{1}{12} *\frac{1}{2} *\frac{1}{4}[/tex][tex]=\frac{1}{96}[/tex]

The function​ s(t) represents the position of an object at time t moving along a line. Suppose s(2)=69 and s(6)=141.Find the average velocity of the object over the interval of time [2,6 ].

Answers

Answer:

The average velocity of the object over the interval of time [2,6] is of 18 units of distance per unit of time.

Step-by-step explanation:

The average velocity can be calculated as the division of the position change by the time change.

Find the average velocity of the object over the interval of time [2,6 ].

6 - 2 = 4 units of time (t, min,...)

s(6) = 141, s(2) = 69

141 - 69 = 72 units of distance(m, km...)

72/4 = 18 u.d./u.t.

The average velocity of the object over the interval of time [2,6] is of 18 units of distance per unit of time.

Which expression and diagram represent “Renee biked four times as far this month as last month”? 4 x right-arrow 4 boxes with x and 4 boxes with minus signs 4 x right-arrow 4 boxes with x 4 + x right-arrow 4 boxes with x and 3 boxes with plus signs x + 4 right-arrow 4 boxes with plus signs

Answers

Answer:

yall the answer is B for 2020 edge

Step-by-step explanation:

I took the test

Answer:

I do agree its B.

Step-by-step explanation:

Why i think this is because my average grade was a 100%

Set F1 = 5N at 0 degrees, F2= 5N at 90 degrees, F3 = 5N at 270 degrees and run the simulation. Using trigonometry, what net force of F4 in the negative x-direction is necessary to produce an angle of 15 degrees between F2 and F3 and the y-axis? Set F4 to that value and run the simulation. Does the angle formed approximate 15 degrees?

Answers

Answer: find the solution in the explanation

Step-by-step explanation:

Let's use resolution of forces by resolving into x - component and y- component.

X - component.

Sum of forces = F1 - F3 - F4cos 15

Sum of forces = 0

5 - 5 - 0.97F4 = 0

- 0.97 F4 = 0

F4 = 0

Y - component

Sum of forces = F2 + F4 sin 15

Sum of forces = 0

5 + 0.26F4 = 0

0.26 F4 = -5

F4 = -5/0.26

F4 = -19.23 N

Simulating F4 back into the equation

Sum of forces = F1 - F3 - F4cos 15

- F4cos Ø = 0

- (-19.23) cos Ø = 0

Cos Ø = 0

Ø = 1

Does the angle formed approximate 15 degrees ? NO

A hose fills a hot tub at a rate of 3.15 gallons per minute. How many hours will it take to fill a 322​-gallon hot​ tub? It will take nothing hours to fill the hot tub. ​(Simplify your answer. Round to two decimal places as​ needed.)

Answers

Answer:

So we find how many of 3.15 units of gallons will fit into the tub.

That means we need to divide. 311/3.15 is about 98.73 minutes

That means that it takes 1 hour and 38.73 mins

Step-by-step explanation:

Solve the equation A = bh for b.

b = Ah

b = A/h

b = h/A

b = h – A

Answers

Answer:

A/h = b

Step-by-step explanation:

A = bh

Divide each side by h

A/h = bh/h

A/h = b

Answer:

[tex]b=\frac{A}{h}[/tex]

Step-by-step explanation:

→To get "b," by itself, all you need to do is divide both sides by "h," like so:

[tex]A=bh[/tex]

[tex]\frac{A}{h} =\frac{bh}{h}[/tex]

[tex]\frac{A}{h} = b[/tex]

. Suppose you randomly choose 10 dentists and ask whether they recommend Colgate toothpaste. What is the probability that exactly 8 dentists in your sample recommend Colgate toothpaste

Answers

Answer:

Step-by-step explanation:

The probability that a dentist recommend Colgate is;

P = 1/2 = 0.5

The probability that a dentist doesn't recommend Colgate is;

P' = 1 - P = 1 -0.5 = 0.5

Of 10 sample dentists, the probability that exactly 8 dentists recommend Colgate toothpaste is;

8 will recommend and two will not recommend it.

P(X) = P^8 × P'^2

P(X) = (0.5)^8 × (0.5)^2

P(X) = 0.0039 x 0.25

P(X) = 0.00098 = 0.098%

Write the standard form of a circle with a center at C(-4, -6) and passes through the point (-1, -2).

Answers

Answer:

(x+4)^2+(y+6)^2 = 25

Step-by-step explanation:

The radius squared is equal to the distance between the center and the point

3^2 + 4^2 = 25

We can shift the center like this

(x+4)^2+(y+6)^2 = 25

Other Questions
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