Answer question 88 They selected a random sample of 30 students fromtheir medium-sized high school to participate. Eachsubject was given 10 minutes to memorize two dif-ferent lists of 20 words, once while listening to musicand once in silence. The order of the two word listswas determined at random; so was the order of thetreatments. The difference in the number of wordsrecalled (music•..SubjectUnscentedScented68.4749.00632.4343.23743.7044.57837.1028.409.31.1728.23silence) was recorded for each1051.2368.47subject. A paired t test on the differences yieldedt = -3.01 and P-value = 0.0027.1165.4051.101258.9383.50(a) State appropriate hypotheses for the paired t test. Besure to define your parameter.1354.4738.301443.5351.37(b) What are the degrees of freedom for the paired t test?1537.9329.33(c) Interpret the P-value in context. What conclusionshould the students draw?1643.5054.271787.7062.73(d) Describe a Type I error and a Type II error in this set-ting. Which mistake could students have made based1853.5358.001964.3052.40on your answer to part (c)?2047.3753.6389. The power of tomatoes Refer to Exercise 87.Explain two ways that the researchers could haveincreased the power of the test to detect u = 0.5.2153.6747.00(a) Explain why it was important to randomly assign theorder in which each subject used the two masks.(b) Do these data provide convincing evidence that thefloral scent improved performance, on average?90. Music and memory Refer to Exercise 88. Which of thefollowing changes would give the test a higher power todetect u = -1: using a =0.01 or α0.10? Explain.87. Growing tomatoes Researchers suspect that Variety Atomato plants have a higher average yield than VarietyB tomato plants. To find out, researchers randomlyselect 10 Variety A and 10 Variety B tomato plants.Then the researchers divide in half each of 10 small91. Significance and sample size A study with 5000subjects reported a result that was statistically signifi-cant at the 5% level. Explain why this result mightnot be particularly large or important.plots of land in different locations. For each plot, acoin toss determines which half of the plot gets a Va-riety A plant; a Variety B plant goes in the other half.After harvest, they compare the yield in pounds forthe plants at each location. The 10 differences in yield(Variety A – Variety B) are recorded. A graph of thedifferences looks roughly symmetric and single-peakedwith no outliers. A paired t test on the differencesyields t = 1.295 and P-value = 0.1138.92. Sampling shoppers A marketing consultantobserves 50 consecutive shoppers at a supermarket,recording how much each shopper spends in thestore. Explain why it would not be wise to use thesedata to carry out a significance test about the meanamount spent by all shoppers at this supermarket.93. Do you have ESP? A researcher looking for evidenceof extrasensory perception (ESP) tests 500 subjects.Four of these subjects do significantly better (P < 0.01)than random guessing.(a) State appropriate hypotheses for the paired t test. Besure to define your parameter.(a) Is it proper to conclude that these four people haveESP? Explain your answer.(b) What are the degrees of freedom for the paired t test?(c) Interpret the P-value in context. What conclusionshould the researchers draw?(b) What should the researcher now do to test whetherany of these four subjects have ESP?94. Ages of presidents Joe is writing a report on thebackgrounds of American presidents. He looks upthe ages of all the presidents when they enteredoffice. Because Joe took a statistics course, he usesthese numbers to perform a significance test aboutthe mean agemakes no sense.(d) Describe a Type I error and a Type II error in thissetting. Which mistake could researchers have madebased on your answer to part (c)?88. Music and memory Does listening to music whilestudying hinder students' learning? Two AP® Sta-tistics students designed an experiment to find out.of all U.S. presidents. Explain why this

Since, we only answer up to three sub-parts of any question, I'll be answering the first three…

They selected a random sample of 30 students from their medium-sized high school to participate. Each subject was given 10 minutes to memorize two dif- ferent lists of 20 words, once while listening to music and once in silence. The order of the two word lists was determined at random; so was the order of the treatments. The difference in the number of words recalled (music – silence) was recorded for each subject. A paired t test on the differences yielded t = -3.01 and P-value 0.0027.