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

In factorial designs, the response produced when the treatments of one factor interact with the treatments of another in influencing the response variable is known as

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 number of degrees of freedom corresponding to between treatments is

Exhibit 10-11 To test whether or not there is a difference between treatments A, B, and C, a sample of 12 observations has been randomly assigned to the 3 treatments. You are given the results below. -Refer to Exhibit 10-11. The null hypothesis

In a completely randomized design involving four treatments, the following information is provided. The overall mean (the grand mean) for all treatments is

Exhibit 10-7 In order to estimate the difference between the average hourly wages of employees of two branches of a department store, the following data have been gathered. -Refer to Exhibit 10-7. A point estimate for the difference between the two sample means is

Guitars R. US has three stores located in three different areas. Random samples of the sales of the three stores (in $1000) are shown below. a.Compute the overall mean. b.State the null and alternative hypotheses to be tested. c.Show the complete ANOVA table for this test including the test statistic. d.The null hypothesis is to be tested at 95% confidence. Determine the critical value for this test. What do you conclude? e. Determine the p-value and use it for the test.

Exhibit 10-5 The following information was obtained from matched samples. -Refer to Exhibit 10-5. The point estimate for the difference between the means of the two populations (Method 1 - Method 2) is

In order to estimate the difference between the average mortgages in the southern and the northern states of the United States, the following information was gathered. a.Compute the degrees of freedom for the t distribution. b.Develop an interval estimate for the difference between the average of the mortgages in the South and North. Let Alpha = 0.03.

In order to test the following hypotheses at an $\alpha$ level of significance, H₀: $\mu$ ₁- $\mu$ ₂ $\le$ 0 H_a: $\mu$ ₁- $\mu$ ₂ > 0 The null hypothesis will be rejected if the test statistic Z is

Three different models of automobiles (A, B, and C) were compared for gasoline consumption. For each model of car, fifteen cars were randomly selected and subjected to standard driving procedures. The average miles/gallon obtained for each model of car and sample standard deviations are shown below. Use the above data and test to see if the mean gasoline consumption for all three models of cars is the same. Let $\alpha$ = 0.05, and use both the critical and p-value approaches.

In order to determine whether or not the means of two populations are equal,

Independent random samples taken on two university campuses revealed the following information concerning the average amount of money spent on textbooks during the fall semester. We want to determine if, on the average, students at University A spent more on textbooks then the students at University B. a.Compute the test statistic. b.Compute the p-value. c.What is your conclusion? Let $\alpha$ = .05.

The following information regarding the number of semester hours taken from random samples of day and evening students is provided. Develop a 95% confidence interval estimate for the difference between the mean semester hours taken by the two groups of students.

In an analysis of variance where the total sample size for the experiment is nT and the number of populations is K, the mean square within treatments is

The business manager of a local health clinic is interested in estimating the difference between the fees for extended office visits in her center and the fees of a newly opened group practice. She gathered the following information regarding the two offices. Develop a 95% confidence interval estimate for the difference between the average fees of the two offices.

Exhibit 10-3 A statistics teacher wants to see if there is any difference in the abilities of students enrolled in statistics today and those enrolled five years ago. A sample of final examination scores from students enrolled today and from students enrolled five years ago was taken. You are given the following information. -Refer to Exhibit 10-3. The 95% confidence interval for the difference between the two population means is

A potential investor conducted a 49 day survey in two theaters in order to determine the difference between the average daily attendance at North Mall and South Mall Theaters. The North Mall Theater averaged 720 patrons per day with a variance of 100; while the South Mall Theater averaged 700 patrons per day with a variance of 96. Develop an interval estimate for the difference between the average daily attendance at the two theaters. Use a confidence coefficient of 0.95.

Exhibit 10-1 Salary information regarding male and female employees of a large company is shown below. -Refer to Exhibit 10-1. At 95% confidence, the margin of error is

In order to estimate the difference between the average Miles per Gallon of two different models of automobiles, samples are taken and the following information is collected. a.At 95% confidence develop an interval estimate for the difference between the average Miles per Gallon for the two models. b.Is there conclusive evidence to indicate that one model gets a higher MPG than the other? Why or why not? Explain.

Exhibit 10-8 In order to determine whether or not there is a significant difference between the hourly wages of two companies, the following data have been accumulated. -Refer to Exhibit 10-8. The test statistic is