Question

A graduate student is interested in how viewing different kinds of scenery affects working memory. For his study, he selects a random sample of 49 adults. The subjects complete a test of working memory before and after walking in a nature setting. Before the walk, the mean score on the test of working memory was 9.4. After the walk, the mean score was 0.9 lower, with a standard deviation of 1.8. The graduate student has no presupposed assumptions about how viewing different kinds of scenery affects working memory, so he formulates the null and alternative hypotheses as: H0: mud = 0 H1: mud 0 He uses a repeated-measures t test. Because the sample size is large, if the null hypothesis is true, the test statistic follows a t-distribution with n-l = 49-l = 48 degrees of freedom. Use the Distributions tool to find the critical region for a = .05. The critical t values, which form the boundaries of the critical region, are. The test statistic is t = Use the tool to evaluate the null hypothesis. (Note: You can place the purple line on your t-statistic to tell whether it lies within or outside the critical region. It's possible that this line may not rest exactly on the t-statistic, but you will be able to tell whether it lies within or outside the critical region.) The t-statistic in the critical region for a two-tailed hypothesis test. Therefore, the null hypothesis is. The graduate student conclude that viewing nature scenery affects working memory.

Answer 1

for 48 degree of freedom and 0.05 level boundaries of the critical region are -/+ 2.407

test statistic          t              =

(x-μ)*√n/s=

33.056

the test statistic is in the critical region, .........null hypothesis is rejected, The graduate student can conclude that ........