i need answers to 16 and 18 please

310 CHAPTER 10 THE TEST FOR TWO INDEPENDENT SAMPLES SS = 11.91, compared to an average of M = 4.3 with after mandatory labeling began in New York City. SS = 9.21 for the n = 12 upper class participants. Although most of the adolescents reported noticing a. Are the data sufficient to conclude that there is a sig- the calorie labels, apparently the labels had no effect nificant mean difference between the two economic on their choices. Data similar to the results obtained populations? Use a two-tailed test with a = .05. show an average of M = 786 calories per meal with b. Construct an 80% confidence interval to estimate s = 85 for n = 100 children and adolescents before the size of the population mean difference the labeling, compared to an average of M = 772 15. Hallam, Price, and Katsarou (2002) investigated the calories with s = 91 for a similar sample of n = 100 after the mandatory posting. influence of background noise on classroom perfor- a. Use a two-tailed test with a = .05 to determine mance for children aged 10 to 12. In one part of the whether the mean number of calories after the study, calming music led to better performance on an arithmetic task compared to a no-music condition. posting is significantly different than before Suppose that a researcher selects one class of n = 18 calorie content was posted. students who listen to calming music each day while b. Calculate r to measure effect size for the mean difference. working on arithmetic problems. A second class of n = 18 serves as a control group with no music. 18. In 1974, Loftus and Palmer conducted a classic Accuracy scores are measured for each child and study demonstrating how the language used to ask the average for students in the music condition is a question can influence eyewitness memory. In M = 86.4 with SS = 1550 compared to an average the study, college students watched a film of an of M = 78.8 with SS = 1204 for students in the no- automobile accident and then were asked questions music condition. about what they saw. One group was asked, "About a. Is there a significant difference between the two how fast were the cars going when they smashed music conditions? Use a two-tailed test with a = .05. into each other?" Another group was asked the same b. Compute the 90% confidence interval for the question except the verb was changed to "hit" in- population mean difference. stead of "smashed into." The "smashed into" group c. Write a sentence demonstrating how the results reported significantly higher estimates of speed than from the hypothesis test and the confidence interval the "hit" group. Suppose a researcher repeats this would appear in a research report. study with a sample of today's college students and obtains the following results. 16. It appears that there is some truth to the old adage "That which doesn't kill us makes us stronger." Seery, Estimated Speed Holman, and Silver (2010) found that individuals with some history of adversity report better mental health Smashed into Hit and higher well-being compared to people with little n = 15 n = 15 or no history of adversity. In an attempt to examine M = 40.8 M = 34.0 this phenomenon, a researcher surveys a group of col- lege students to determine the negative life events that SS = 510 SS = 414 they experienced in the past 5 years and their current feeling of well-being. For n = 18 participants with 2 a. Do the results indicate a significantly higher esti- or fewer negative experiences, the average well-being mated speed for the "smashed into" group? Use a score is M = 42 with SS = 398, and for n = 16 par- one-tailed test with a = .01. ticipants with 5 to 10 negative experiences the average b. Compute the estimated value for Cohen's d to score is M = 48.6 with SS = 370. measure the size of the effect. a. Is there a significant difference between the two c. Write a sentence demonstrating how the results of populations represented by these two samples? the hypothesis test and the measure of effect size Use a two-tailed test with a = .01. would appear in a research report. b. Compute Cohen's d to measure the size of the effect. 19. Numerous studies have found that males report higher c. Write a sentence demonstrating how the outcome self-esteem than females, especially for adolescents of the hypothesis test and the measure of effect (Kling, Hyde, Showers, & Buswell, 1999). Typical size would appear in a research report. results show a mean self-esteem score of M = 39.0 with SS = 60 2 fo