1 The mean blood cholesterol concentration of a large population of adults (50-60 years old) is 200 mg/dL with a standard deviation of 20 mg/dL.
1 The mean blood cholesterol concentration of a large population of adults (50-60 years old) is 200 mg/dL with a standard deviation of 20 mg/dL. Answer the following questions:
(a) Assuming normality, what is the probability that a randomly selected individual from this age group will have a blood cholesterol level below 250 mg/dL?
(b) What is the probability that the mean of a sample of 100 adults from this age group will have a value above 205 mg/dL?
(c) What is the probability that the mean of a sample of 100 adults from this age group will have a value below 203 mg/dL?
2. Portions of prepared luncheon meats should have pH values with a mean of 5.6 and standard deviation of 1.2. The usual quality control procedure is to ran- domly sample each consignment of meat by testing the pH value of 36 portions. The consignment is rejected if the pH value of the sample mean exceeds 6.0.
(a) Do you need to use a correction factor with this problem (Yes or No)? (b) What is the probability of a consignment being rejected?
3.Blood coagulation and clot formation in humans is a complicated process with at least 13 different plasma coagulation factors involved. One of the more impor- tant protein factors is called prothrombin, which must be converted into the enzyme thrombin for coagulation to occur. Individuals with vitamin K deficiency are thought to have low prothrombin levels as a result.
Twenty (20) patients with vitamin K deficiency were randomly chosen and their pro- thrombin levels were measured. The mean prothrombin level for the sample was 20 mg/100 ml and the variance was 121 (mg/100 ml)2. Note: the 100 ml is just the unit and not part of the mean or variance. Calculate a 90% confidence interval for the true mean prothrombin in vitamin K deficient patients. Round any computations to 4 decimal places.
