Question 3 An SRS of 20 recent birth records at the local hospital were selected. In the sample, the average birth weight was 121.4 ounces and the standard deviation was 7.5 Complete ounces. Assume that in the population of all babies born in this hospital, the birth weights follow a Normal distribution, with some mean / Mark 0.0 out of 1.0 P Flag question Reference: Ref 16-1 A 90% confidence interval for the population mean birth weight based on these data is Select one Da. 121.4 1 4.80 ounces. O b. 121.4 + 3.29 ounces O c. 121.4 + 2.89 ounces. O d. 121.4 + 5.63 ounces. Question 4 Do students tend to improve their math SAT scores the second time they take the test? A random sample of four students who took the test twice received the following complete score Mark 1.0 out of 1.0 Student 1 2 3 4 450 520 720 600 P Flag question First score Second score 440 600 720 630 Assume that the change in math SAT score (second score - first score) for the population of all students taking the test twice is Normally distributed, with mean /. A 90% confidence interval for / is Select one: O a. 25.0 + 64.29. O b. 25.0 + 43.08 O c. 25.0 + 47.54. O d. 25.0 + 33.24. Question 5 A special diet is intended to reduce the cholesterol of patients at risk of heart disease. If the diet is effective, the target is to have the average cholesterol of this group be Complete below 200. After six months on the diet, an SRS of 50 patients at risk for heart disease had an average cholesterol of 192, with standard deviation s = 21. Is this Mark 0.0 out of sufficient evidence that the diet is effective in meeting the target? Assume the distribution of the cholesterol for patients in this group is approximately Normal with 1.0 mean u P Flag question A 95% confidence interval for the average cholesterol of patients at risk for heart disease who have been on the diet for six months is Select one a. 192 + 10.61. O b. 192 + 8.23 c. 192 + 5.97. O d. 192 +7.54. Question 7 Bags of a certain brand of tortilla chips claim to have a net weight of 14 ounces. Net weights actually vary slightly from bag to bag and are Normally distributed with Not answered mean . A representative of a consumer advocate group wishes to see if there is any evidence that the mean net weight is less than advertised and so intends to test the Marked out of hypotheses 1.0 P Flag question Ho: H = 14, Hai U