Exam 11: Two Sample Tests of Hypothesis

i. The rejection region for analysis of variance is in the upper tail of the F distribution. ii. In ANOVA, k -1 degrees of freedom are associated with the numerator of the F ratio. iii. In ANOVA, k-1 degrees of freedom are associated with the denominator of the F ratio.

i. One characteristic of the F distribution is that F cannot be negative. ii. The shape of the F distribution is determined by the degrees of freedom for the F-statistic, one for The numerator and one for the denominator. iii. The F distribution's curve is positively skewed.

Which statement is correct about the F distribution?

i. One characteristic of the F distribution is that F cannot be negative. ii. One characteristic of the F distribution is that computed F can only range between -1 and +1. iii. The shape of the F distribution is positively skewed.

Suppose we select 20 observations from each of five treatments. The appropriate degrees of Freedom are:

i. To employ ANOVA, the populations being studied must be approximately normally distributed. ii. A technique that is efficient when simultaneously comparing more than two population means is Known as analysis of variance (ANOVA). iii. The least number of sources of variation in ANOVA is two.

i. The test statistic used in ANOVA is t. ii. The calculated F value must be equal to or greater than one (1). iii. The shape of the F distribution is symmetrical.

The annual dividend rates for a random sample of 16 companies in three different industries, Utilities, banking, and insurance were recorded. The ANOVA comparing the mean annual dividend Rate among three industries rejected the null hypothesis that the dividend rates were equal. The Mean Square Error (MSE) was 3.36. The following table summarized the results: The interval is [3.38, 8.18]. Based on the comparison between the mean annual dividend rate for Companies in the utilities and insurance industries, _______________________.

Given the following Analysis of Variance table for three treatments each with six observations. What is the decision?

i. The F distribution is positively skewed and its values may range from 0 to plus infinity. ii. The F distribution's curve is positively symmetrical. iii. Like Student's t distribution, a change in the degrees of freedom causes a change in the shape of The F distribution.

The plant manager believes that the temperature in the packaging area of the plant affects the daily Rate of production. To investigate, the plant temperature is set at 18 degrees, 20 degrees, and 22 Degrees. The number of units produced at each of these temperatures for a sample of days is Collected. Using this output, what conclusions can you draw?

Suppose that an automobile manufacturer designed a radically new lightweight engine and wants To recommend the grade of gasoline to use. The four grades are: below regular, regular, premium, And super premium. The test car made three trial runs on the test track using each of the four Grades. Assuming any grade can be used at the 0.05 level, what is the critical value of F using 0.05 Level of significance?

Which of the following is NOT a characteristic of the F distribution?

The components of an ANOVA table include:

Using the Excel printout below to compare the mean annual incomes for executives with Undergraduate and Master's Degree or more, the following statements can be made:

Given the following Analysis of Variance table for three treatments each with six observations. What is the computed value of F?

i. If we want to determine which treatment means differ, one method is confidence intervals. ii. If the confidence interval includes 0, there is no difference in the pair of treatment means. iii. If both end points of a confidence interval are of the same sign, it indicates that the treatment Means are not different.

Suppose that an automobile manufacturer designed a radically new lightweight engine and wants To recommend the grade of gasoline to use. The four grades are: below regular, regular, premium, And super premium. The test car made three trial runs on the test track using each of the four Grades. Is there a difference in the performance between the four grades of gas? If you were to use Excel to assist in your solution to this problem, which test would you use?

Two accounting professors decided to compare the variation of their grading procedures. To Accomplish this they each graded the same 10 exams with the following results: What are the degrees of freedom for the denominator of the F ratio?

The annual dividend rates for a random sample of 16 companies in three different industries, Utilities, banking, and insurance were recorded. The ANOVA comparing the mean annual dividend Rate among three industries rejected the null hypothesis that the dividend rates were equal. The Mean Square Error (MSE) was 3.36. The following table summarized the results: Compare the mean annual dividend rate for companies in the utilities and insurance industries and Construct the 95% confidence interval.