A toy manufacturer wants to know how many new toys children buy each year. A sample of 305 children was taken to study their purchasing habits. Construct the 80% confidence interval for the mean number of toys purchased each year if the sample mean was found to be 7.6. Assume that the population standard deviation is 1.5. Round your answers to one decimal place.

Answers

Answer 1

Answer:

The 80% confidence interval for the mean number of toys purchased each year is between 7.5 and 7.7 toys.

Step-by-step explanation:

We have that to find our [tex]\alpha[/tex] level, that is the subtraction of 1 by the confidence interval divided by 2. So:

[tex]\alpha = \frac{1 - 0.8}{2} = 0.1[/tex]

Now, we have to find z in the Ztable as such z has a pvalue of [tex]1 - \alpha[/tex].

That is z with a pvalue of [tex]1 - 0.1 = 0.9[/tex], so Z = 1.28.

Now, find the margin of error M as such

[tex]M = z\frac{\sigma}{\sqrt{n}}[/tex]

In which [tex]\sigma[/tex] is the standard deviation of the population and n is the size of the sample.

[tex]M = 1.28\frac{1.5}{\sqrt{305}} = 0.1[/tex]

The lower end of the interval is the sample mean subtracted by M. So it is 7.6 - 0.1 = 7.5

The upper end of the interval is the sample mean added to M. So it is 7.6 + 0.1 = 7.7

The 80% confidence interval for the mean number of toys purchased each year is between 7.5 and 7.7 toys.


Related Questions

Which triangles are similar to triangle ABC ?

Answers

Answer:

both of em

Step-by-step explanation:

What is 5 3/4 -1 5/12= ?

Answers

Answer:

4.33333333333 or 4 and 1/3

Step-by-step explanation:

Answer:

4 1/3

Step-by-step explanation:

1) Convert 5 3/4 to improper fraction.

2) Simplify 5x4 to 20.

3) Simplify 20+3 to 23.

4) Convert 1 5/12 to an improper fraction.

5) Simplify 1x12 to 12.

6) Simplify 12+5 to 17.

7) Find the least common denominator of 23/4 & 17/12.

8) Make the denominators the same.

9) Join the denominators.

10) Simplify 52/12 ( 4 1/3 )

Hope this helped!

​  

.

Can someone help me!

Answers

Answer:

m∠A = 48.81°

Step-by-step explanation:

Given triangle is a right triangle and we have to measure ∠A.

Since, opposite side and adjacent sides of angle A has been given

So we will apply tangent rule to get the measure of angle A.

tan(∠A) = [tex]\frac{\text{Opposite side}}{\text{Adjacent side}}[/tex]

tan(∠A) = [tex]\frac{8}{7}[/tex]

∠A = [tex]\text{tan}^{-1}(\frac{8}{7})[/tex]

∠A = 48.814

  ≈ 48.81°

o put on Your Thinking Cap!
$ Challenging Practice
1.
Michelle got an average score of 80 on two tests. What score must
she get on the third test so that her average score for the three tests
is the same as the average score for the first two tests?

Answers

Answer:

Michelle must get an 80 on her next test to keep her average score.

Step-by-step explanation:

Since Michelle got an average score of 80 on two tests, to determine what score she must get on the third test so that her average score for the three tests is the same as the average score for the first two tests, the following calculation must be performed:

X / 2 = 80

X = 80 x 2

X = 160

X x 3 = 80 x 3

X x 3 = 240

X = 240/3

x = 80

So, Michelle must get an 80 on her next test to keep her average score.

WITH STEPS PLEASEE..

Answers

Answer:

16+3y=31

3y=31-16

3y=15

y=15/3

y=5

check.

16+3×5

=16+15

=31

The answer for this is Y=5

40 POINTS !! 40 POINTS !!

PLEASE HELP , DONT SKIP !

NO LINKS OR FILES.

Answers

Answer:

<5,2>

Step-by-step explanation:

Hii! I really need help on this with the spree that answers! For 30 points. I don’t wanna waste my points so make sure your answer is right.

Answers

Step-by-step explanation:

1. K = 13 (13+5=18)

2. X= 36 (36-12=24)

3. Y = 14 (17=3+14)

4. Z= 24(22=24-2)

5. A=7 (divide both sides by 4)

6. H=12 (12/6=2)

7. B= 10 (100=10*10)

8. Y=42 (6=42/7)

I'm pretty sure that this is correct.

1. K+5=18
-5 = -5

k=13

2. x-12=24
+12 = +12

x=36


3.17=3+y
-3 = -3

y=14

4.22=z-2
+2 = +2

z=24

5.4a=28
÷4 = ÷4

a=7

6.h/6=2
×6 = ×6

h=12

7.100=10b
÷10 = ÷10

b=10

8.6=y/7
×7 = ×7

y=42

ZABC and ZQRS are supplementary angles.
If the measure of ZABC = 140°, what is the
measure of ZQRS?
O
mZQRS = [?]
Enter

Answers

40° is your answer

Answer:

:

< ABC+<QRS=180

m<QRS=180-140=40°

URGENT PLZ HELP!!!!!

Answers

Answer:

30% man this easy

Step-by-step explanation:

PLS GIMME BRAINLIEST PLS

A car rental company is interested in the amount of time its vehicles are out of operation for repair work. A random sample of 21 cars showed that, over the past year, the numbers of days that each of these cars had been inoperative were as follows: 15, 11, 19, 24, 6, 18, 20, 15, 18, 12, 14, 19, 5, 21, 12, 11, 8, 10, 7, 2, 14 Assuming that the population is normally distributed, construct a 95% confidence interval for the mean number of days that vehicles in the company's fleet are out of operation.

Answers

Answer:

(10.891; 15.869)

Step-by-step explanation:

Given the data::

15, 11, 19, 24, 6, 18, 20, 15, 18, 12, 14, 19, 5, 21, 12, 11, 8, 10, 7, 2, 14

The confidence interval is obtained using the relation :

Mean ± margin of error

Margin of Error = Zcritical * s/sqrt(n)

Using a calculator, the mean value of the data and standard deviation above is :

Mean = Σx / n ; n = sample size

Mean, xbar = 281 / 21

Mean = 13.38

Standard deviation , s = sqrt[Σ(X - xbar)²/ n-1]

Standard deviation, s = 5.82

Margin of Error = Zcritical * s/sqrt(n)

Zcritical at 95% confidence level = 1.96

Margin of Error = 1.96 * 5.82/sqrt(21) = 2.489

Confidence interval :

Mean ± margin of error

13.38 ± 2.489

Lower boundary = (13.38 - 2.489) = 10.891

Upper boundary = (13.38 + 2.489) = 15.869

(10.891; 15.869)

Adam bought 6 yogurt cups for $8. Which of the following represents a higher unit rate than what Adam paid?

a. 4 yogurt cups for $6
b. 8 yogurt cups for $10
c. 10 yogurt cups for $12
d. 12 yogurt cups for $14​

Answers

Answer:

A, 4 yougurt cups for $6

Step-by-step explanation:

The reason I did the math myself. Sorry if its incorrect.

The sum of 9 and a number is less than 12. Which of the following inequalities expresses the solutions ?

Answers

The answer is 2 cause If you subtract 12 from 9 you’ll get 2.

Which of the following is the equation of the circle shown below?

Answers

Answer:

Step-by-step explanation:

Center is 6, -2

Radius is 7

(x-6)^2 + (y + 4)^2 = 7^2

==============

Please give brainliest, I really want to rank up, thank you!

Consider function f, where B is a real number.

f(x)=tan(Bx)

Complete the statement describing the transformations to function f as the value of B is changed.

As the value of B increases, the period of the function (remains the same, increases, decreases), and the frequency of the function (remains the same, increases, decreases).
When the value of B is negative, the graph of the function (reflects over the y-axis, remains the same, reflects over the x-axis).

Answers

Using the concept of the tangent function, it is found that:

As the value of B increases, the period of the function decreases, and the frequency of the function increases. When the value of B is negative, the graph of the function reflects over the y-axis.

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

Tangent function:

It is given by:

[tex]f(x) = \tan{Bx}[/tex]

The period is [tex]P = \frac{\pi}{|B|}[/tex].The frequency is [tex]F = \frac{1}{P} = \frac{|B|}{\pi}[/tex].

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

The period is inversely proportional to B, thus, as B increases, the period decreases.Frequency is inversely proportional to the period, thus, as the period decreases, the frequency increases.When B is negative, we get [tex]f(x) = \tan{-Bx} = f(-x)[/tex], thus, the function is reflected over the y-axis, as the graph at the end of the answer shows, with f(x) is red(B positive) and f(-x) in blue(B negative).

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

Considering the three bullet points above, the correct option is:

As the value of B increases, the period of the function decreases, and the frequency of the function increases. When the value of B is negative, the graph of the function reflects over the y-axis.

A similar problem is given at https://brainly.com/question/16828446

Answer:

got it right

Step-by-step explanation:

the difference between the squares of two numbers is 32. twice the square of the first number increased by the square of the second number is 76. find the numbers.​

Answers

Answer:

The numbers are 6 and 2

6 squared = 36

2 squared = 4

So 36-4 = 32

And 36 x 2 = 72 + 4 = 76

A friend tells you about a recent study dealing with the number of years of teaching experience among current college professors. He remembers the mean but can't recall whether the standard deviation was 6 months, 6 years or 16 years. Which was it?

Answers

Answer:

6 years

Step-by-step explanation:

Bob mixed 5/8 cup of water and 1/8 cup of lemon juice in a cup. The rest of the mixture was lime juice. How much lime juice did Bob add if the cup was full?

Answers

Answer: thats a good question

Step-by-step explanation:

Answer: he will add 2/8 more so it can be full.

Step-by-step explanation: you divide 2/8 by 5/8 and you'll get 1/8.

please give me brainlest

2. The area A of a circle is increasing at a constant rate of 2.5cm s . If the area of the circle is given
by A = πr2, what is the rate of change of the radius when the radius is 15cm?

Answers

Answer:

235.65 cm^2s-1

Step-by-step explanation:

We have that;

Rate of change of area (dA/dt) = (dA/dr) (dr/dt) By chain rule

Note that dr/dt = rate of change of radius

But

A = πr^2

dA/dr = 2πr

dr/dt = 2.5cm s-1 (given)

So;

dA/dt =  2πr * 2.5cm s-1

r = 15cm (given)

dA/dt = 2 * 3.142 * 15cm * 2.5cm s-1

dA/dt = 235.65 cm^2s-1

Solve the following equation without using a calculator.

log3(81)=y

Answers

Answer:hmmvb

Step-by-step explanation:

Amy buys 22 envelopes for 13p each and pays with a £5 note.
How much change does she get?
Give your answer in pounds, £.​

Answers

hi there lol have a great day

Paige only needs to sell to 17 more customers to receive a bonus. She works part time, so she only talks to 50 customers per day. With a sales ratio of 1:9, on which day will Paige qualify for a bonus?

Answers

Answer:

Paige will qualify for a bonus on her 4th day of work.

Step-by-step explanation:

50 customers per day

needs to sell to 17

Ratio = 1:9

      1:9

×17         ×17

    17:153

Paige needs to see 153 customers.

153 ÷ 50 = 3.06 ≈ 4   (As the answer is not asking for the exact number of the day you round up to make a whole day without underestimating)

So, Paige will qualify for a bonus on her 4th day of work.

Help how do you simplify this????!!!

Answers

3/5? you can’t simplify it anymore

Answer:

3/5

Step-by-step explanation: its on the page the yellow text you add the top numbers but the bottem number stays the same

11 divided by 3 2/3 with step by step explination

Answers

Answer:

3

Step-by-step explanation:

11/1 divided by 11/3

keep change flip to get:

11/1 x 3/11

and multiply to get:

33/11

Simplify to get:

3/1 or 3

Answer:

3

Step-by-step explanation:

step one is to make the fraction into a unbalanced fraction

step two is to make it a proper fraction by switching the values (I am talking about 2 2/3s so you know)

Then remove the greatest common factor, so 11, and only three remains

Select all the expressions that are equivalent to 16x + 36
16(x + 20)
x(16 + 36)
4(4x + 9)
2(8x + 18)
2(8x + 36)

Answers

Answer:

2(8x+18)

multiply the values in the bracket with 2

2×8x=16x

2×18=36

16x + 36

Answer: 2(8x+18)   ,4(4x+9)

Step-by-step explanation:

16 x+36 =4(4x+9)=2(8x+18)

if you add an exclamation I will give you a Brain list


A male animal can weigh up to 6,000 pounds.
How many tons is 6,000 pounds?
6,000 pounds is equivalent to what
tons.

Answers

Answer:

it would be 3 tons if I'm correct

Answer: 3 tons

Step-by-step explanation:

1 ton is equal to 2,000 pounds.

Divide 6,000 from 2,000 to find how many tons the animal weighs.

6,000/2,000=3.

Hope this helps!

Show all work to factor x4 − 10x2 + 9 completely.

Answers

Answer:

(x+3)(x-3)(x+1)(x-1)

Proof:https://www.symbolab.com/solver/step-by-step/x%5E%7B4%7D-10x%5E%7B2%7D%2B9

what is the answer. Evalute (2/3)2. Thank you

Answers

Answer:

4/3

Step-by-step explanation:

Answer:

hi

Step-by-step explanation:

[tex] { \frac{2}{3} }^{2} = \frac{4}{9} [/tex]

have a nice day

A billard ball has a surface area of 84 square centimeters. What is the radius of the ball?​

Answers

Answer: √21/√pi

Step-by-step explanation: Surface area of ball is 4(pi)r^2. Divide 84 by 4 and get 21. Dividing 21 by pi and taking the square root therefore is the answer.

ten vegetable selections available, how many 3 vegetable plates can be made

Answers

10x9x8=270 plates can made

Please help! What is the population of people?? Answer and explanation please! no links :\

Answers

Answer:

36043.305

Step-by-step explanation:

My brain is so tired I can't-

Multiply all the numbers with the information they gave you, then add them all.

I REALLY HOPE THIS HELPED MY BRAIN NEEDS A BREAK

Other Questions
When given the picture using what you know find the answer. What is m For what cellular function does the breathing rate help regulate? In which Africa climate region would you most like to live in and why Find the following ratios. Write each answer as a fraction and as a decimal rounded to four decimal places. What is the correct way to write the following sentences from the passage?What I meant, Dad said, was that you should wear dress pants or a dress, or anything nice besides jeans. This is a concert, not a baseball game. X 6.4.7-TQuestion HelpAssume that females have pulse rates that are normally distributed with a mean of j = 74.0 beats per minute and a standard deviation of o = 12.5 beats per minute. Complete parts (a) through (c) below.a. If 1 adult female is randomly selected, find the probability that her pulse rate is between 70 beats per minute and 78 beats per minute.The probability is(Round to four decimal places as needed.)Enter your answer in the answer box and then click Check Answer2 partsremaining Plz help me I am timed!! Solve 2\3 = 1/4 kbtw it algebra if an angle measures 18 what is the measure of its complement 4. On the basis of what criteria did Linnaeus classify natural bodies"into his system? Finnhas$60inasavingsaccount.Theinterestrateis10%peryearandisnotcompounded.Howmuchinterestwillheearnin1year?Use the formula i = prt, where i is the interest earned, p is the principal (starting amount), r is the interest rate expressed as a decimal, and t is the time in years. Two investments totallng $47,500 produce an annual income of $3000. One investment ylelds 9% per year, while the other yields 6% per year. How much is invested at each rate? Select the correct word(s) from the drop down menu to finish the following sentences:Fish in the ocean can be caught by anyone, and it is difficult to prevent people from fishing, in this sense, fish in the oceans are_____. If I catch a fish, that means there is one less fish in the sea for someone else to catch. Therefore, fish are_____. Considering those two characteristics, fish in the ocean are____. Brown v. Board, Main points, argument, and violations. I am expecting a decent paragraph! (10 Sentence!) Majority Opinion for the brief also! Who can help me with my missing assignments it is in Spanish and the subject is reading please help Which excerpt from The Telephone: A Truer Tale best supports the purpose of the text?After all, it has a terrific happy ending in which the hero, Alexander Graham Bell, uses his astonishing new device to transmit the words Mr. Watson, come here. I want to see you.Meucci would not allow himself to become discouraged, however. Instead, he returned to his lab determined to make his talking machine even better. He worked for many more years and did just that.In 1871, Meucci still lacked investors and was unable to pay the $250 patent fee, so he filed a patent caveat instead. A patent caveat cost only $10 and would not allow anyone else to patent the same idea for one full year.On June 11, 2002, one hundred and twenty-six years after Bells patent was issued, the United States House of Representatives passed a resolution recognizing Antonio Meucci as the true inventor of the telephone. how can I subtract 4/3 - 1/3 The attraction between water molecules and a Nation or a Clion occurs because water molecules are A.nonpolarBsymmetrical.polar.Dlinear. what happens during subduction Read the temp what is it?17.3 or 17.25??