answer all questions A graduate student is interested in how viewing different types of scenes affects working memory. For his study, he selects a random sample of 36adults. The subjects complete a series of working memory tests before and after walking in an urban setting.Before the walk, the mean score on the test of working memory was 9.1. After the walk, the mean score was 1.4 higher.The graduate student has no presupposed assumptions about how viewing different types of scenes affects working memory, so he formulates the nulland alternative hypotheses as:Ho : Pp - 0H : Pp * 0Assume that the data satisfy all of the required assumptions for a repeated-measures t test. The graduate student calculates the following statisticsfor his hypothesis test:Mean difference (Mp)1.4Estimated population standard deviation of the differences (s)1.6Estimated standard error of the mean differences (SMD)0.2667Degrees of freedom (df)35The t statistic5.25The critical values of t when a = .05=2.030Notice that since the t statistic (5.25) is in the critical region (t 2.030), the hypothesis test is significant when a = .05.A 95% confidence interval for the mean difference isUse Cohen's d to calculate the effect size. The absolute value of the estimated d isUsing Cohen's criteria, this is av effectsize.Use r to calculate the effect size. The r is v . This value of r means that, on average,9% of the variability in the working memory isexplained by whether it was measured before or after the walk. (Round to the nearest percent.) Suppose a sleep researcher wonders whether playing classical music while getting ready for bed helps people fall asleep faster. He has 20 studyparticipants sleep two nights in the sleep lab. For one of those nights, the researcher has each study participant listen to classical music for 15minutes before getting into bed. For the other night (the control night), the room is quiet. (The researcher varies which night the study participantslisten to the music so that 10 of the participants have the control night first and the other 10 have the classical music night first.) The researcher thenmeasures the study participants' sleep latency-that is, the number of minutes it takes for them to fall asleep.At the end of the study, the researcher looks at the distribution of the sleep latencies and notices that some people fell asleep immediately, whereasothers took over an hour to fall asleep. In addition, the differences in each participant's sleep latencies between the two nights are mostly fewer than10 minutes, but for five of the participants, the difference is close to an hour.Would it be valid for the sleep researcher to use the independent-measures t test to test whether playing classical music before going to bed shortenssleep latency?O Yes, if his sample size is 230 or the raw scores are normally distributed.O No, because he does not have homogeneity of variance.O No, because the sleep researcher is using a repeated-measures (within-subjects) research design. In this type of design, the studypopulations are not independent.O Yes.

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answer all questions A graduate student is interested in how viewing different types of scenes affects working memory. For his study, he selects a random sample of 36adults. The subjects complete a series of working memory tests before and after walking in an urban setting.Before the walk, the mean score on the test of working memory was 9.1. After the walk, the mean score was 1.4 higher.The graduate student has no presupposed assumptions about how viewing different types of scenes affects working memory, so he formulates the nulland alternative hypotheses as:Ho : Pp - 0H : Pp * 0Assume that the data satisfy all of the required assumptions for a repeated-measures t test. The graduate student calculates the following statisticsfor his hypothesis test:Mean difference (Mp)1.4Estimated population standard deviation of the differences (s)1.6Estimated standard error of the mean differences (SMD)0.2667Degrees of freedom (df)35The t statistic5.25The critical values of t when a = .05=2.030Notice that since the t statistic (5.25) is in the critical region (t < -2.030 or t> 2.030), the hypothesis test is significant when a = .05.A 95% confidence interval for the mean difference isUse Cohen's d to calculate the effect size. The absolute value of the estimated d isUsing Cohen's criteria, this is av effectsize.Use r to calculate the effect size. The r is v . This value of r means that, on average,9% of the variability in the working memory isexplained by whether it was measured before or after the walk. (Round to the nearest percent.) Suppose a sleep researcher wonders whether playing classical music while getting ready for bed helps people fall asleep faster. He has 20 studyparticipants sleep two nights in the sleep lab. For one of those nights, the researcher has each study participant listen to classical music for 15minutes before getting into bed. For the other night (the control night), the room is quiet. (The researcher varies which night the study participantslisten to the music so that 10 of the participants have the control night first and the other 10 have the classical music night first.) The researcher thenmeasures the study participants' sleep latency-that is, the number of minutes it takes for them to fall asleep.At the end of the study, the researcher looks at the distribution of the sleep latencies and notices that some people fell asleep immediately, whereasothers took over an hour to fall asleep. In addition, the differences in each participant's sleep latencies between the two nights are mostly fewer than10 minutes, but for five of the participants, the difference is close to an hour.Would it be valid for the sleep researcher to use the independent-measures t test to test whether playing classical music before going to bed shortenssleep latency?O Yes, if his sample size is 230 or the raw scores are normally distributed.O No, because he does not have homogeneity of variance.O No, because the sleep researcher is using a repeated-measures (within-subjects) research design. In this type of design, the studypopulations are not independent.O Yes.

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