Butter and margarine contain saturated fat, which can increase the “bad” cholesterol in your blood. In order to advise clients, a dietitian examined four types of margarine. A random sample of each type was obtained, and the amount of saturated fat (in grams) per serving was recorded.
a. Conduct an analysis of variance test to show that there is evidence of an overall difference in population mean saturated fat per serving
b. Construct the Tukey 99% confidence intervals to isolate the pairs of means contributing to the overall difference.
c. Are the differences found in part (b) consistent with the percentage of fat indicated on each product label? If not, can you explain any discrepancy?
According to the U.S. Environmental Protection Agency, a typical American family washes about 400 loads of laundry each year. Front-loading washing machines have become popular because they have a small carbon footprint, use less electricity, and tend to get clothes cleaner. Independent random samples of front-loading washing machines were obtained and the amount of water used (in gallons) in a regular load was measured for each.
a. Conduct an analysis of variance test to show that there is evidence of an overall difference in population mean water usage.
b. Construct the Bonferroni 95% confidence intervals to isolate the pairs of means contributing to the difference.
c. Construct the Tukey 95% confidence intervals to isolate the pairs of means contributing to the overall difference.
d. Are the results the same in parts (b) and (c)? If so why? If not, why not?