## to carry out a hypothesis test

:  12. The records of a casualty insurance company show that, in the past, its clients have had a mean of 1.7 auto accidents per day with a variance of 0.0016 . The actuaries of the company claim that the variance of the number of accidents per day is no longer equal to 0.0016 . Suppose that we want to carry out a hypothesis test to see if there is support for the actuaries’ claim. State the null hypothesis H0 and the alternative hypothesis H1 that we would use for this test.H0 :  H1 :

|

## this proportion has changed

:  11. A decade-old study found that the proportion of high school seniors who felt that “getting rich” was an important personal goal was 70% . Suppose that we have reason to believe that this proportion has changed, and we wish to carry out a hypothesis test to see if our belief can be supported. State the null hypothesis H0 and the alternative hypothesis H1 that we would use for this test.H0 :  H1

|

## the null hypothesis

10. A coin-operated drink machine was designed to discharge a mean of 6 ounces of coffee per cup. Suppose that we want to carry out a hypothesis test to see if the true mean discharge differs from 6 . State the null hypothesis H0 and the alternative hypothesis H1 that we would use for this test.H0 :  H1 :

|

## the sample malfunction

9. A researcher wishes to estimate the proportion of X-ray machines that malfunction. A random sample of 200 machines is taken, and 70 of the machines in the sample malfunction. Based upon this, compute a 90% confidence interval for the proportion of all X-ray machines that malfunction. Then find the lower limit and upper limit of the 90% confidence interval.  Carry your intermediate computations to at least three decimal places. Round your answers to two decimal places. (If necessary, consult a list of formulas.)Lower limit:Upper limit:

|

## ComputeStandard error

8. Do pregnant women give birth the week of their due date? A study claims that 12% of the population of all pregnant women actually gave birth the week of their due date. You are a researcher who wants to test this claim, so you will select a random sample of 60 women who have recently given birth.Follow the steps below to construct a 95% confidence interval for the population proportion of all pregnant women who gave birth the week of their due date. Then state whether the confidence interval you construct contradicts the study’s claim. (If necessary, consult a list of formulas.)(a)Click on “Take Sample” to see the results from the random sample.  Take SampleNumberProportionGave birth the week of due dateDid not give birth the week of due dateEnter the values of the sample size, the point estimate of the population proportion, and the critical value you need for your 95% confidence interval. (Choose the correct critical value from the table of critical values provided.) When you are done, select “Compute”.Critical values=z0.0052.576=z0.0102.326=z0.0251.960=z0.0501.645=z0.1001.282Sample size: Point estimate: Critical value: ComputeStandard error: Margin of error: 95% confidence interval:     (b)Based on your sample, graph the 95% confidence interval for the population proportion of all pregnant women who gave birth the week of their due date.

• Enter the values for the lower and upper limits on the graph to show your confidence interval.
• For the point (), enter the claim 0.12 from the study.

95% confidence interval:01    (c)Does the 95% confidence interval you constructed contradict the claim from the study? Choose the best answer from the choices below. No, the confidence interval does not contradict the claim. The proportion 0.12 from the study is inside the 95% confidence interval. No, the confidence interval does not contradict the claim. The proportion 0.12 from the study is outside the 95% confidence interval. Yes, the confidence interval contradicts the claim. The proportion 0.12 from the study is inside the 95% confidence interval. Yes, the confidence interval contradicts the claim. The proportion 0.12 from the study is outside the 95% confidence interval.

|

## the true mean of all scores.

6. The standard deviation of test scores on a certain achievement test is 11.5. A random sample of 90 scores on this test had a mean of 75.3. Based on this sample, find a 90% confidence interval for the true mean of all scores. Then give its lower limit and upper limit.Carry your intermediate computations to at least three decimal places. Round your answers to one decimal place. (If necessary, consult a list of formulas.)Lower limit:Upper limit:

|

## phonesSample meanSample standard deviation

5. A cell phone manufacturer tests the battery lifetimes of its cell phones by recording the time it takes for the battery charges to run out while testers are playing games on the phones continuously. The manufacturer claims that the population mean of the battery lifetimes of all phones of their latest model is 7.22 hours. As a researcher for a consumer information service, you want to test that claim. To do so, you select a random sample of 45 cell phones of the manufacturer’s latest model and record their battery lifetimes. Assume it is known that the population standard deviation of the battery lifetimes for that cell phone model is 2.73 hours.Based on your sample, follow the steps below to construct a 99% confidence interval for the population mean of the battery lifetimes for all phones of the manufacturer’s latest model. Then state whether the confidence interval you construct contradicts the manufacturer’s claim. (If necessary, consult a list of formulas.)(a)Click on “Take Sample” to see the results from your random sample of 45 phones of the manufacturer’s latest model.Take SampleNumber of phonesSample meanSample standard deviationPopulation standard deviation2.73Enter the values of the sample size, the point estimate for the population mean, the population standard deviation, and the critical value you need for your 99% confidence interval. (Choose the correct critical value from the table of critical values provided.) When you are done, select “Compute”.Critical values=z0.0052.576=z0.0102.326=z0.0251.960=z0.0501.645=z0.1001.282Sample size: Point estimate: Population standard deviation: Critical value: ComputeStandard error: Margin of error: 99% confidence interval:     (b)Based on your sample, graph the 99% confidence interval for the population mean of the battery lifetimes for all phones of the manufacturer’s latest model.

• Enter the lower and upper limits on the graph to show your confidence interval.
• For the point (), enter the manufacturer’s claim of 7.22 hours.
|

## IQ scores

4. A researcher wants to investigate the effects of environmental factors on IQ scores. For an initial study, she takes a sample of 400 people who grew up as the only child. She finds that 53% of them have an IQ score over 100. It is known that 50% of the general population has an IQ score exceeding 100.Answer the following. (If necessary, consult a list of formulas.)(a)Find the mean of p, where p is the proportion of people with IQ scores over 100 in a random sample of 400 people.(b)Find the standard deviation of p.(c)Compute an approximation for Pp0.53, which is the probability that there will be 53% or more individuals with IQ scores over 100 in a random sample of 400. Round your answer to four decimal places.  5.

|

## national and cultural identity

In what way do contemporary artists consider issues of national and cultural identity? What are their strategies for calling traditional divisions into question through their art? Use at least two art examples to support your post.

Should be 75-150 words in length.

|

## cinema and theatre

Respond to the following in a minimum of 175 words:

Movies and stage plays, also known as cinema and theatre, are probably the most accessible of the performing arts. In both forms, a story is portrayed using similar methods or elements such as actors and actresses, costumes, sets, scripts, and lighting. Both film and theatre producers are able to bring a story to life using these elements, and their artistic choices can enhance the drama of the story.

Think of one of your favorite movies and consider how different artistic choices were made in the film’s production. Which elements were most effective and why? Could your film be turned into a stage play? Why or why not?

|