Exam 14: Analysis of Categorical Data

THE NEXT QUESTIONS ARE BASED ON THE FOLLOWING INFORMATION: A production manager was interested in the relationship between the amount of overtime incurred over a week and the total level of output for the week.The manager collected data over a 12-week period.The data are presented below: -Test the null hypothesis of no association between the amount of overtime incurred over a week and the total level of output for the week against the alternative of positive association.

It is known that the coefficients of skewness and kurtosis for the standard normal distribution are 0 and 3,respectively.

The method for determining the number of degrees of freedom for the chi-square distribution depends on the type of test being done.

Nonparametric tests are often preferred to parametric tests since they do not rely on the normality assumption of the underlying population distribution.

THE NEXT QUESTIONS ARE BASED ON THE FOLLOWING INFORMATION: An airline is considering changing the color scheme of its planes' interiors.A focus group of 220 people was asked which color scheme they preferred.Of those who expressed a preference,87 preferred the new color scheme,while 121 preferred the old. -For a random sample of 250 observations,the skewness of the data was calculated to be -0.25,while the kurtosis was calculated to be 3.25.Is there sufficient evidence to reject the null hypothesis of normality for this data?

A measure of correlation that is not susceptible to serious influence by extreme values and on which valid tests can be based on general population distributions is obtained through the use of ranks.

A statistical test that determines the likelihood that sample data have been generated from a population that conforms to a specified type of probability distribution is known as a contingency-table test.

The nonparametric tests like the Sign test,the Wilcoxon rank sum test,the Mann-Whitney test,and the Wilcoxon signed rank test require that the probability distributions be:

Which of the following tests employs matched-pairs sampling?

Under the null hypothesis that the population distribution is normal,the test statistic for the Jarque-Bera test for normality has a chi-square distribution with degrees of freedom equal to:

The middle 0.90 portion of the chi-square distribution with 12 degrees of freedom has table values of 5.23 and 21.03,respectively.

THE NEXT QUESTIONS ARE BASED ON THE FOLLOWING INFORMATION: Three choices of free gifts are offered to 270 persons who subscribed to a new magazine.The number of subscribers choosing each gift is shown in the table below.Assume the null hypothesis that the gifts are equally attractive to the subscribers.Use a 0.01 significance level. -Compute the test statistic.

THE NEXT QUESTIONS ARE BASED ON THE FOLLOWING INFORMATION: A large city is in the process of voting on a bond issue to build a covered sports arena.A local political analyst wishes to determine if the level of income will impact on the decision of the voters.He takes a sample of 350 who plan to vote in the upcoming election. Vote on Bond Issue -What is the expected frequency of the $50,000 and over and No categories?

In goodness-of-fit-test,the expected frequencies are based on the:

THE NEXT QUESTIONS ARE BASED ON THE FOLLOWING INFORMATION: A large department store records the number of returns per day in women's dresses for reasons such as wrong size;husband didn't like it,color,etc.The manager of the women's dresses department recalls from her statistics class in college that the Poisson distribution might describe such events.A random sample of 150 days is taken.The number of returns per day in the sample as well as the observed frequencies is shown in the table below: She tests the hypothesis that returns per day are Poisson distributed with a population mean equal to 1.90.Her significance level is 0.05 -Identify the critical value.

A two-independent sample t-test corresponds to a Wilcoxon signed rank test for paired samples.

THE NEXT QUESTIONS ARE BASED ON THE FOLLOWING INFORMATION: A brand manager is interested in determining if consumers prefer the new fragrance associated with a detergent.She surveyed 212 consumers and has them rank the new and old fragrances on a scale of 1 to 10.Of the 198 consumers who scored a different score on the new fragrance than on the old,the absolute values of the differences in their ratings were ranked.The smaller of the ranked sums,8,208,was for those individuals who rated the original fragrance higher. -A sample of 15 managers in retail stores having self-checkout was asked if their customers have a positive attitude about the scanning process.Ten managers answered "yes," and five answered "no." Test against a two-sided alternative the null hypothesis that,for the population of managers,responses would be equally divided between "yes" and "no."

For a random sample of 247 observations,the skewness of the data was calculated to be -0.52 while the kurtosis was calculated to be 3.24.Which of the following is true in the light of the information given above?

The number of degrees of freedom for a contingency table with r rows and c columns is equal to rc,provided that both r and c are greater than or equal to 2.

THE NEXT QUESTIONS ARE BASED ON THE FOLLOWING INFORMATION: A recent survey asked 124 purchasing managers what they thought would happen to inflation over the next quarter.Of those managers who thought the inflation rate would change,73 thought inflation would be higher,while 40 thought it would be lower. -Is this sufficient evidence to conclude that the consensus opinion is that inflation is heading higher?