Exam 10: Comparisons Involving Means, Experimental Design and Analysis of Variance

Exhibit 10-9 Two major automobile manufacturers have produced compact cars with the same size engines. We are interested in determining whether or not there is a significant difference in the MPG (miles per gallon) of the two brands of automobiles. A random sample of eight cars from each manufacturer is selected, and eight drivers are selected to drive each automobile for a specified distance. The following data show the results of the test. -Refer to Exhibit 10-9. The test statistic is

Exhibit 10-4 The following information was obtained from independent random samples. Assume normally distributed populations with equal variances. -Refer to Exhibit 10-4. The standard error of is

Exhibit 10-15 The following is part of an ANOVA table that was obtained from data regarding three treatments and a total of 15 observations. -Refer to Exhibit 10-15. The computed test statistics is

If we are interested in testing whether the mean of population 1 is significantly different from the mean of population 2, the correct null hypothesis is

The ANOVA procedure is a statistical approach for determining whether or not

Exhibit 10-4 The following information was obtained from independent random samples. Assume normally distributed populations with equal variances. -Refer to Exhibit 10-4. The 95% confidence interval for the difference between the two population means is

The three major automobile manufacturers have entered their cars in the Indianapolis 500 race. The speeds of the tested cars are given below. At $\alpha$ = .05, test to see if there is a significant difference in the average speeds of the cars of the auto manufacturers. Use both the critical and p-value approaches.

An experimental design where the experimental units are randomly assigned to the treatments is known as

Recently, a local newspaper reported that part time students are older than full time students. In order to test the validity of its statement, two independent samples of students were selected. a.Give the hypotheses for the above. b.Determine the degrees of freedom. c.Compute the test statistic. d.At 95% confidence, test to determine whether or not the average age of part time students is significantly more than full time students.

Exhibit 10-6 The management of a department store is interested in estimating the difference between the mean credit purchases of customers using the store's credit card versus those customers using a national major credit card. You are given the following information. -Refer to Exhibit 10-6. At 95% confidence, the margin of error is

In the ANOVA, treatment refers to

Exhibit 10-10 -Refer to Exhibit 10-10. The null hypothesis

Exhibit 10-6 The management of a department store is interested in estimating the difference between the mean credit purchases of customers using the store's credit card versus those customers using a national major credit card. You are given the following information. -Refer to Exhibit 10-6. A point estimate for the difference between the mean purchases of the users of the two credit cards is

Exhibit 10-1 Salary information regarding male and female employees of a large company is shown below. -Refer to Exhibit 10-1. The point estimate of the difference between the means of the two populations is

The F ratio in a completely randomized ANOVA is the ratio of

To construct an interval estimate for the difference between the means of two populations when the standard deviations of the two populations are unknown and it can be assumed the two populations have equal variances, we must use a t distribution with (let n₁ be the size of sample 1 and n₂ the size of sample 2)

In a completely randomized experimental design, 7 experimental units were used for the first treatment, 9 experimental units for the second treatment, and 14 experimental units for the third treatment. Part of the ANOVA table for this experiment is shown below. a.Fill in all the blanks in the above ANOVA table. b.At 95% confidence using both the critical value and p-value approaches, test to see if there is a significant difference among the means.

In hypothesis testing if the null hypothesis is rejected,

Exhibit 10-15 The following is part of an ANOVA table that was obtained from data regarding three treatments and a total of 15 observations. -Refer to Exhibit 10-15. If at 95% confidence, we want to determine whether or not the means of the populations are equal, the p-value is

If we are interested in testing whether the mean of population 1 is significantly larger than the mean of population 2, the correct null hypothesis is