he U.S. Department of Health monitors fishing waters, to determine if the bacteria count has risen above a maximum safe level of 70. The following observations were obtained from 9 random samples of a stream: 69, 74, 75, 70, 72, 73, 71, 73, and 68.  Can you say that the bacteria are above the safe level (alpha=0.05)? Calculate the appropriate test statistic. What is the critical value for the test? Would you issue a warning about the bacteria levels in the stream? Why?

In a study conducted in Italy, 10 patients with hypertriglyceridemia were placed on a low-fat, high-carbohydrate diet. Before the start of the diet, cholesterol and triglyceride measurements were recorded for each subject. Patient Cholesterol Level (mmol/l) Triglyceride level (mmol/l) 1 5.12 2.30 2 6.18 2.54 3 6.77 2.95 4 6.65 3.77 5 6.36 4.18 6 5.90 5.31 7 5.48 5.53 8 6.02 8.83 9 10.34 9.48 10 8.51 14.20 a. Construct a two-way scatter plot for these data. b. Use STATA to calculate Pearson’s Correlation Coefficient for these data. c. Test, α = 0.05, whether or not the population correlation, ρ, equals 0.

Suppose the National Transportation Safety Board wants to examine the safety of compact cars, midsize cars, and full-size cars. It collects a sample of three for each of the treatments (cars types). Test the claim that the mean pressure applied to the driver's head during a crash is equal for all three types of cars. Use a = 0.05 Compact Cars 643 Midsize Cars 469 Full-size Cars 484 655 m 427 456 20 Apple 702 525 A 402 Show your 6 steps labeled in order in the box below using the p-value method.