Problem Set: Chapter 11 The t Test for Two Related Samples 6. A one-tailed hypothesis test for a repeated-measures design A cognitive psychologist is interested in whether increasing reading speed reduces comprehension. She has students complete a reading comprehension task before and after a six-week speed-reading course. In the beginning of the study, a randomly selected group of 81 students scored an average of 107 points on the reading comprehension task. Since the sample size is larger than 30, the cognitive psychologist can assume that the sampling distribution of Mp is normal. She plans to use a repeated- measures t test. The cognitive psychologist identifies the null and alternative hypotheses as: H. : UD H, : UD Use the Distributions tool to find the critical region(s) for a = 0.01. The critical t score, which is the value for t scores that separates the tail(s) from the main body of the distribution and forms the critical region(s), is (Hint: Remember to set the degrees of freedom on the tool and to consider whether this is a one-tallied or two-tailed test.) * Distribution 4.0 23.0 20 -1.0 0.0 2.0 3.0 40Problem Set: Chapter 11 The t Test for Two Related Samples 4.0 -3.0 2.0 -1.0 0.0 3.0 0 071 9.090 0.631 After the speed reading course, the students scored an average of 7 points lower than before they began the speed-reading course. The standard deviation of the difference scores was's = 12. To calculate the t statistic, you must first calculate the estimated standard error. The estimated standard error is . (Note: For best results, retain at least four decimal places from your calculation of the estimated standard error for use in calculating the t statistic.) Calculate the t statistic, The t statistic is Use the tool to evaluate the null hypothesis. The t statistic win the critical region for a one-tailed hypothesis test. Therefore, the null hypothesis is .The cognitive psychologist w conclude that increasing reading speed reduces comprehension, Grade It Now Save & Continue Continue without saving