Exam 14: Chi-Square Tests

As an independent project,a team of statistics students tabulated the types of vehicles that were parked in four different suburban shopping malls. Assuming independence,the expected frequency of SUVs in Jamestown is

A chi-square goodness of fit test for a normal distribution used 60 observations,and the mean and standard deviation were estimated from the sample.The test used seven categories.We would use how many degrees of freedom in looking up the critical value for the test?

To carry out a chi-square goodness-of-fit test for normality you need at least

In a chi-square goodness-of-fit test,we gain one degree of freedom if n increases by 1.

In a chi-square test of a 5 × 5 contingency table at α = .05,the critical value is 37.65.

Observed frequencies in a chi-square goodness-of-fit test for normality may be less than 5,or even 0,in some cells,as long as the expected frequencies are large enough.

Which of the following is not a potential solution to the problem that arises when not all expected frequencies are 5 or more in a chi-square test for independence?

The chi-square test is unreliable when there are any cells with small observed frequency counts.

You want to test the hypothesis that the prime rate and inflation are independent.The following table is prepared for the test on the basis of the results of a random sample,collected in various countries and various time periods,shown below. Using α = .05,which is the critical value of the test statistic that you would use?

The table below is a tabulation of opinions of employees of Axolotl Corporation,who were sampled at random from pay records and asked to complete an anonymous job satisfaction survey,with the results shown below. Assuming independence,the expected frequency of satisfied hourly employees is

A taste test of randomly selected students was conducted to see if there was a difference in preferences among four popular drinks.The following table shows the frequency of responses. Using α = .025,the critical value of the test you would use in determining whether the preferences are the same among the drinks is

The Oxnard Retailers Anti-Theft Alliance (ORATA)published a study that claimed the causes of disappearance of inventory in retail stores were 30 percent shoplifting,50 percent employee theft,and 20 percent faulty paperwork.The manager of the Melodic Kortholt Outlet performed an audit of the disappearance of 80 items and found the frequencies shown below.She would like to know if her store's experience follows the same pattern as other retailers. Using α = .05,the critical value you would use in determining whether the Melodic Kortholt Outlet's pattern differs from the published study is

Employees of OxCo Mfg.were surveyed to evaluate the company's pension plan.The table below displays some of the results of the survey. Which is the most appropriate conclusion?

The chi-square test can only be used to assess independence between two variables.

Probability plots are used to test the assumption of normality.

Which data set is consistent with the hypothesis of a normal population?

In an ECDF test for goodness-of-fit,the n observations are grouped into categories rather than being treated individually.

Preferences for the type of diet drink from a random sample of 121 shoppers are in the table below.A researcher is interested in determining if there is a relationship between the type of diet drink preferred and the age of the shoppers. Using α = .025,what is the critical value of the test statistic that you would use in a decision rule to test an appropriate hypothesis?

Preferences for the type of diet drink from a random sample of 121 shoppers are in the table below.A researcher is interested in determining if there is a relationship between the type of diet drink preferred and the age of the shoppers. What can you conclude for the data analysis at α = .05?

Kortholts that fail to meet certain precise specifications must be reworked on the next day until they are within the desired specifications.A sample of one day's output of kortholts from the Melodic Kortholt Company showed the frequencies shown below. Find the chi-square test statistic for a hypothesis of independence.