Question

7. Miller (1956), in a classic study, demonstrated that participants can store a fixed amount of words in their short term memory. You believe you can train students to be able to increase their short term memory by having them generate a story to connect the words they are supposed to memorize together. You pre-test a group of 22 participants to see how many words they are able to remember from a list. Then you train the participants to be able to make a story from the words on the list so that they can remember more. After the training you give them a post-test. You expect that they will be able to remember more words after the training (i.e. that the post-test will be higher than the pre-test). Analyze the data below with a paired samples one-tailed t test, and write a conclusion statement. Show your work.

Pretest mean = 6

Posttest mean = 9

Standard error of the difference = 0.9

Answer 1

It was that the post-test will be higher than the pre-test

So,

It is given that

Pretest mean = 6

Posttest mean = 9

Standard error of the difference = 0.9 and sample size n = 22

t test statistics

degree of freedom = n- 1 = 22- 1 = 21

Now using the excel function T.DIST(x, df) or t distribution table

setting x = -15.63 and df= 21

we get

p value = 0.0000

p value is significant at 0.05 or 0.01 level of significance because p value is less than significance level. Rejecting the null hypothesis and concluding that there is sufficient evidence to support the claim that the post-test will be higher than the pre-test