1. To estimate the mean triglyceride levels of people in West Palm Beach, a blood test on 30 randomly selected people was conducted and yielded a mean triglyceride level of 220, with a standard deviation of 12. Construct a 95% confidence interval for the true average triglyceride level of people in West Palm Beach. Round your answer to three decimal places. (3 points)

• a. (218.868, 229.132)
• b. (215.519, 224.481)
• c. (214.967, 233.033)
• d. (219.741, 230.259)

2.The regression equation, y = 6.5x + 20, is obtained after performing a regression analysis, where x represents the number of hours studied for an exam and y represents the marks on the exam. Is the following statement true or false regarding the analysis above? (2 points)

If the regression square (R^ 2) is 0.11, the number of hours studied is very useful for predicting the exam marks.

• a. True
• b. False