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A publisher reports that 50%50% of their readers own a particular make of car. A marketing executive wants to test the claim that the percentage is actually different from the reported percentage. A random sample of 240240 found that 45%45% of the readers owned a particular make of car. Determine the P-value of the test statistic. Round your answer to four decimal places.

Country Financial, a financial services company, uses surveys of adults age 18 and older to determine if personal financial fitness is changing over time (USA Today, April 4, 2012). In February 2012, a sample of 1000 adults showed 410 indicating that their financial security was more than fair. In February 2010, a sample of 900 adults showed 315 indicating that their financial security was more than fair. State the hypotheses that can be used to test for a significant difference between the population proportions for the two years. What is the sample proportion indicating that their financial security was more than fair in 2012? In 2010? Conduct the hypothesis test and compute the p-value. At a .05 level of significance, what is your conclusion? What is the 95% confidence interval estimate of the difference between the two population proportions?

15 To perform a test of hypothesis that the population slope parameter is zero, the test statistic t is ______. a 14.487                 b 16.097                 c 17.885                 d 19.873

A company that has a 15% market share launches a marketing campaign. At the end of the campaign period, the company conducts a survey in order to assess whether its market share has increased. From a survey issued to 500 customers after the campaign, the company found that 90 of them were committed to their products.  a.  Write the null and alternative hypotheses. b.  What is the value of the test statistic? c.  What is the associated P-value? d.  State your conclusion using α = 0.05.

(Ch8) True or False? With a given sample, when we lower the confidence level, it will reduce the width of a confidence interval of the population proportion.

Researchers conducted a prospective cohort study to assess the association between dietary supplements and cognitive ability among children. A total of 500 children age 12-17 years who take an omega-3 fatty acid supplement are compared with 500 children age 12-17 years who do not take an omega-3 fatty acid supplement. Researchers follow the children for 2 years. During this time, 300 children who take the supplement earn what is classified as a “high” score on a cognitive test while 200 children who do not take the supplement earn what is classified as a “high” score on the same cognitive test.  Show calculations.    a) Construct a 2x2 table from the information presented above b) The risk difference is:

Consider the following hypothesis test: H 0:   50 H a:  > 50 A sample of 55 is used and the population standard deviation is 7. Use the critical value approach to state your conclusion for each of the following sample results. Use  = .05. With  = 52.5, what is the value of the test statistic (to 2 decimals)?Can it be concluded that the population mean is greater than 50?Select Yes No Item 2 With  = 51, what is the value of the test statistic (to 2 decimals)?Can it be concluded that the population mean is greater than 50?Select Yes No Item 4 With  = 51.8, what is the value of the test statistic (to 2 decimals)?Can it be concluded that the population mean is greater than 50?

Mary Arnold wants to use the results of a random sample market survey to seek strong evidence that her brand of breakfast cereal has more than 20% of the total market. Formulate the null and alternative hypotheses, using P as the population proportion.

7. A television station wishes to study the relationship between viewership of its 11 p.m. news program and viewer age (18 years or less, 19 to 35, 36 to 54, 55 or older). A sample of 250 television viewers in each age group is randomly selected, and the number who watch the station’s 11 p.m. news is found for each sample. The results are given in the table below.

A recent study focused on the number of times men and women send a Twitter message in a day. The information is summarized here:    Sample Size Sample Mean Population Standard Deviation Men 31 29 5 Women 36 34 10 At the 0.01 significance level, we ask if there is a difference in the mean number of times men and women send a Twitter message in a day. Assume that women are Population 1 and men are Population 2. What is the value of the test statistic for this hypothesis test?   a. 2.907   b. 2.641   c. 2.815   d. 2.911

The null and alternate hypotheses are:   H0 : μd ≤ 0 H1 : μd > 0   The following sample information shows the number of defective units produced on the day shift and the afternoon shift for a sample of four days last month.     Day   1 2 3 4 Day shift 11 12 13 19 Afternoon shift 9 10 14 15     At the 0.025 significance level, can we conclude there are more defects produced on the day shift? Hint: For the calculations, assume the day shift as the first sample.   State the decision rule. (Round your answer to 2 decimal places.)     Compute the value of the test statistic. (Round your answer to 3 decimal places.)     What is the p-value?   multiple choice 1 Between 0.05 and 0.10 Between 0.001 and 0.005 Between 0.005 and 0.01     What is your decision regarding H0?   multiple choice 2 Do not reject H0 Reject H0

The U.S. Census Bureau conducts annual surveys to obtain information on the percentage of the voting-age population that is registered to vote.  Suppose that 450 employed persons and 477 unemployed persons are independently and randomly selected, and that 291 of the employed persons and 242 of the unemployed persons have registered to vote.  Can we conclude that the percentage of employed workers ( p1 ), who have registered to vote, exceeds the percentage of unemployed workers ( p2 ), who have registered to vote?  Use a significance level of α=0.05 for the test. Step 3 of 6 :  Compute the weighted estimate of p, p‾ . Round your answer to three decimal places.

The U.S. Census Bureau conducts annual surveys to obtain information on the percentage of the voting-age population that is registered to vote.  Suppose that 450 employed persons and 477 unemployed persons are independently and randomly selected, and that 291 of the employed persons and 242 of the unemployed persons have registered to vote.  Can we conclude that the percentage of employed workers ( p1 ), who have registered to vote, exceeds the percentage of unemployed workers ( p2 ), who have registered to vote?  Use a significance level of α=0.05 for the test. Step 2 of 6 :  Find the values of the two sample proportions, pˆ1 and pˆ2 . Round your answers to three decimal places.

The U.S. Census Bureau conducts annual surveys to obtain information on the percentage of the voting-age population that is registered to vote.  Suppose that 450 employed persons and 477 unemployed persons are independently and randomly selected, and that 291 of the employed persons and 242 of the unemployed persons have registered to vote.  Can we conclude that the percentage of employed workers ( p1 ), who have registered to vote, exceeds the percentage of unemployed workers ( p2 ), who have registered to vote?  Use a significance level of α=0.05 for the test. Step 1 of 6 :  State the null and alternative hypotheses for the test.

A company is considering an organizational change which entails adopting the use of self-managed work teams which they hope will lead to higher levels of employee satisfaction.  In order to assess the attitudes of employees of the company towards this change a sample of 250 employees was selected and asked whether they favor the institution of self-managed teams.  Three responses were allowed: favor, neutral or oppose.  The observed frequency of the results of the survey are shown below:         Opinion   Type of Job Favor Neutral Oppose Total Hourly Worker 25 40 35 100 Supervision 45 35 20 100 Manager 20 15 15 50 Total 90 90 70 250         Use this data to test the hypothesis that opinion and type of job are independent at the .025 level.

The manager of a men’s clothing catalog measured the market’s response to a $6 decrease in the usual price of his company’s oxford shirts by conducting a sales experiment.  An A-B split was used to divide the company’s 120,000-customer mailing list into two groups.  Customers in the control group were sent catalogs listing oxford shirts at their usual price of $40.  Customers in the test group were sent catalogs listing the price of oxford shirts at $32.80.  During the period of the test, customers in the control group purchased 700 oxford shirts, and customers in the test group purchased 889 oxford shirts. What is the independent variable in this sales experiment?  What is the dependent variable in this sales experiment? What is the percent change in price in this experiment?   What is price elasticity indicated by the results of this experiment.

A report on the U.S. economy indicates that 30% of Americans have experienced difficulty in making mortgage payments.  A news organization randomly sampled 400 Americans from 10 cities named the “fastest dying cities in the U.S.” (Forbes Magazine, August 2008) and found that 140 reported such difficulty. Does this indicate that the problem is more severe among these cities? a.  Write the null and alternative hypotheses. b.  What is the value of the test statistic? c.  What is the associated P-value? d.  State your conclusion using α = 0.05.

In studying his campaign plans, Mr. Singleton wishes to estimate the difference between men's and women's views regarding his appeal as a candidate. He asks his campaign manager to take two random independent samples and find the 80%80% confidence interval for the difference. A random sample of 508508 male voters and 605605 female voters was taken. 108108 men and 193193 women favored Mr. Singleton as a candidate. Find this confidence interval. Step 1 of 4 :   Find the values of the two sample proportions, pˆ1�^1 and pˆ2�^2. Round your answers to three decimal places.

The sample means, x¯ , is an example of ...   Group of answer choices     an interval estimate   a population parameter   a point estimate   a population statistic

A hypothesis will be used to test that a population mean equals 9 against the alternative that the population mean is less than 9 with known variance . What is the critical value for the test statistic for the significance level of 0.025? Round your answer to two decimal places (e.g. 98.76).

Is it true or false that endogenous sample selection will not cause bias in the OLS estimator.

Suppose employers care about overall productivity Z, which is made up of two components, X and Y, such that Z=X+Y (and employers know this productivity function). Suppose there are two groups (male and female) whose average Zs are the same (i.e. Z_M =Z_F), but X_M < X_F and Y_M > Y_F (and again, employers know these population averages). Researchers decide to run a resume-based audit study where they randomize names based on gender (using typically male or female names) but hold constant Y. They provide no information on X. Which of the following would suggest taste-based discrimination? ● The call-back rate is the same for both sexes. ● The call-back rate is higher for men than for women ● We can't use differences in call-back rates to find suggestive evidence of taste-based discrimination because there's too many other factors that are different across the resumes. ● The call-back rate is higher for women than for men

ou are conducting a hypothesis test on the body weights of male fraternity members. The research (alternative) hypothesis is that the averge weight is greater than 200 lbs. Your test will be at the 0.01 significance level. You take a sample of 64 men, and find that the sample average is 210 lbs, and the standard deviation is 20 lbs. The value of your test statistic is, therefore, 4.00. Would your test statistic be higher or lower if your sample stats had been estimated from a sample of 640 men, rather than 64?  Group of answer choices Lower The same (neither higher, nor lower). Higher

We are interested in analysing the effect of the lockout laws introduced in some areas of the Sydney CBD and nearby surrounds on the number of alcohol-related violent incidents.  Suppose we have two samples of data on the number of violent incidents in a number of local areas of the Sydney CBD and nearby surrounds. Pubs, hotels and clubs located in a subset of these areas became subject to the lockout laws when they were introduced in 2014. The first sample is from 2010 before the introduction of the lockout laws, and the second is from 2015 after the introduction of the law. The hypothesis we wish to test is that the introduction of the lockout laws reduces violent incidents in the areas in which the lockout laws were put in place.  We use a difference-in-difference model on the pooled data from 2010 and 2015. We find the following results: viol_inc hat = 33.21 (5.29) + 12.43lockout (7.01) – 4.19Yr2015 (2.98) – 3.32 (lockout x Yr2015) (1.85) N = 181, R^2 = 0.128 Where: viol_incis the…

Why does a confidence interval contain more information than the resultof a single hypothesis test?

In your own words, discuss the relationship between a t-test and a confidence interval.