Question

For questions 1 through 3 state the proper t-test (one sample, paired samples, independent samples) that should be used to evaluate the research question: (*Just state the test)

1) A developmental psychologist wants to determine if a recently created computer training program can increase the working memory ability of high-school students. A sample of 40 students are given the reverse digit span test at the beginning of the school year and then again after 4 weeks of training. Are there significant changes from pre- to -post?

2) A representative from Pepsi believes that Pepsi is a better testing soda than Coca-Cola and wants to test this officially. At an FAU tailgate 40 students are invited to participate in a taste testing. Twenty students are asked to rate how much they like Pepsi on a scale of 1-10 and the other 20 are asked to rate how much they like coca cola? Is the mean score significantly higher for the Pepsi group or the Coca-Cola group?

3) The national average GRE score on the math section is a 136. A graduate coordinator would like to determine if a sample of 20 students who applied to graduate school at FAU score significantly different from average.

Complete an independent samples t-test for the following example: Are the exam scores higher for group 1 (Freshman) compared to group 2 (Sophomores). Each group contains 30 students.

Group 1: Mean score 94, variance of 100

Group 2: Mean score 98, variance of 110

4a. Provide the standard deviation of the distribution of differences between means

4b. Provide the t-score and critical t-value

4c. Are the exam scores significantly different between groups?

Answer 1

1

It is paired t test. The scores digit span test is taken before and after the training session.

Hence it is paired t test

2.

Independent samples. Rating of two different drinks Pepsi an Coca cola are compared.

Two samples are being compared.

3.

It is one sample test. The hypothesis to be tested if the mean average GRE score on the math section is 136 or not

4.