Exam 11: Two Sample Tests of Hypothesis

A manufacturer of automobile transmissions uses three different processes. The management Ordered a study of the production costs to see if there is a difference among the three processes. A Summary of the findings is shown below. What is the mean square for treatments?

A random sample of 30 executives from companies with assets over $1 million was selected and Asked for their annual income and level of education. The following table summarized the results: Using this output, what conclusions can you draw?

i. If the computed value of F is 4.01 and the critical value is 2.67, we would conclude that all the Population means are equal. ii. Not rejecting the null hypothesis in ANOVA indicates that the population means are equal. iii. The null hypothesis for an ANOVA is µ1 - µ2 = µ3.

A manufacturer of automobile transmissions uses three different processes. The management Ordered a study of the production costs to see if there is a difference among the three processes. A Summary of the findings is shown below. What is the sum of squares for the treatment?

A random sample of 30 executives from companies with assets over $1 million was selected and Asked for their annual income and level of education. The ANOVA comparing the average income Among three levels of education rejected the null hypothesis. The Mean Square Error (MSE) was 243)7. The following table summarized the results: When comparing the mean salaries to test for differences between treatment means, the t statistic Is based on:

i. The statistical technique used to test the equality of three or more population means is called Analysis of variance (ANOVA). ii. To employ ANOVA, the populations should have approximately equal standard deviations. iii. The least number of sources of variation in ANOVA is two.

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 is H0?

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 skewed. iii. There is one, unique F distribution for a F-statistic with 29 degrees of freedom in the numerator And 28 degrees of freedom in the denominator.

Several employees have submitted different methods of assembling a product. Sample data for Each method are: How many treatments are there?

i. For the population means, the alternate hypothesis used in the analysis of variance test states that Μ1 = µ2 = µ3. ii. For an ANOVA test, rejection of the null hypothesis does not identify which populations differ Significantly. iii. If the computed value of F is 4.01 and the critical value is 2.67, we would conclude that all the Population means are equal.

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 is the critical value of F at the 0.01 level of significance?

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: At the 5% level of significance, what is the decision?

In ANOVA analysis, when the null hypothesis is rejected, we can find which means are different by:

i. For an ANOVA test, rejection of the null hypothesis does not identify which populations differ Significantly. ii. Not rejecting the null hypothesis in ANOVA indicates that the population means are equal. iii. The null hypothesis for an ANOVA is µ1 - µ2 = µ3.

Three different advertisements were used to sell a popular toy. In computing F, how many degrees Of freedom are there in the numerator?

In an effort to determine the most effective way to teach safety principles to a group of employees, Four different methods were tried. Some employees were given programmed instruction booklets And worked through the course at their own pace. Other employees attended lectures. A third Group watched a television presentation, and a fourth group was divided into small discussion Groups. A high of 10 was possible. Samples of five tests were selected from each group. The test Grade results were: Excel's summary results at the 0.05 level produce the following output: Using this output, what conclusions can you draw?

An electronics company wants to compare the quality of their cell phones to the cell phones from Three competitors. They sample 10 phones from each company and count the number of defects for Each phone. If ANOVA is used to compare the average number of defects, the treatments would be Defined as:

i. 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. ii. Like Student's t distribution, a change in the degrees of freedom causes a change in the shape of The F distribution. iii. The calculated F value must be equal to or greater than zero (0).

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: Using Excel to assist in the comparison, what test would be used?

In ANOVA, an F statistic is used to test a null hypothesis such as: