Question

In a larger company, a survey was conducted in collaboration with occupational health care and health surveys. In addition, blood samples were taken on all employees. One of the samples was serum cholesterol, and the mean value among women was 4.8 mmol / l. Over the next two years, health-focused activities were conducted, primarily around diet and exercise. As part of a larger evaluation, a number of variables were measured from a random sample of 121 women at the company. The following results were obtained for serum cholesterol: the mean μ = 4.68 mmol / l, s = 0.82. a) Did the mean serum cholesterol differ in the current study from the previously known mean? Conduct a hypothesis test. b) Establish a confidence interval for current serum cholesterol and increase the confidence interval. Also use the confidence interval to conduct a hypothesis test.

Answer 1