Place all answers, work, and graphs in this document.

Use alpha = .05 for all hypothesis testing questions.

** Please use non-directional two-tailed tests for these questions (not one-tailed tests).

1. Recall that the dataset, Stat_grades.sav, contains data for a sample of 105 statistics students. One of the variables in this dataset is called, review. This variable is either “1” for “NO” (did not attend the review sessions), or “2” for “YES” (did attend the review sessions).  In other words, the Instructor for all the students decided to provide additional optional review opportunities for students to learn the class materials. To accomplish this, the Instructor offered all students the option to attend a set of review sessions. The Instructor believes that offering these review sessions will help student performance. Using the appropriate statistical test, methods, and evaluations, determine if attending the Review sessions made a significant difference in students Total Points. Be sure to include each step of the process, any SPSS results used, an interpretation of the results, and the final conclusions.

(a) What is the hypothesis being tested here?

(b) What are Ho and Ha?

(c) What is the name of the test you will run? Run the appropriate SPSS test and include the SPSS output here.

(d) What are the results of the test? What is the p-value and is it larger or smaller than the alpha value – show your work and explain the result.

 (e) Write a conclusion for the above in plain English so that any person could understand. What can you say about the review and its effect on total points and student overall performance?

2. Based on many years of past classes and experience, the Instructor for the students in the Stat_Grades.sav dataset has determined that a successful mean value for Final Exam Points is 57 points. Does the Final Exam Points for the students in Stat_Grades.sav differ significantly from the known success value of 57 points? Use and include the appropriate statistical test, methods, and evaluations. Be sure to include each step of the process, any SPSS results used, an interpretation of the results, and final conclusions.

(a) What is the hypothesis being tested here?

 (b) What are Ho and Ha?

(c) What is the name of the test you will run? Run the appropriate SPSS test and include the SPSS output here.

(d) What are the results of the test? What is the p-value? Compare the p value to alpha and note the result.

 (e) Explain the conclusion in plain English so that any person could understand. Did the students in Stat_Grades.sav do significantly differently than the population mean of 57? How did they do and what did you find. Explain.

3. Using the Stat_Grades.sav dataset, compare Quiz 1 and Quiz 5 and determine if there is a statistically significant difference in the average student performance between these two quizzes. Use and include the appropriate statistical test, methods, and evaluations. Be sure to include each step of the process, any SPSS results used, an interpretation of the results, and final conclusions.

(a) What is the hypothesis being tested here?

(b) What are Ho and Ha?

(c) What is the name of the test you will run? Run the appropriate SPSS test and include the SPSS output here.

(d) What are the results of the test? What is the p-value? Compare the p value to alpha and note the result.

(e) Explain the result and conclusion of the test in plain English so that any person could understand.

4. Use the following SPSS output to answer these questions. The hypothesis here is: “Is there a significant difference in Final Exam Points between the two gender groups?”

(a) What is Ho and Ha?

(b) What t-test is being used?

(c) What is the p value? (Assume equal variances)

(d) Using alpha at .05, what is the result of this test?

(e) Write the full conclusion for this test in plain English for normal people.

(f) How many males are in this sample of data? Is the mean points for males different than for females? Is it significantly different? What does it mean to be significantly different (versus just different)?