1. It is known that the serum cholesterol level of females is normally distributed and its population variance is 41 mg/mL. Researchers decided to estimate the population's mean serum cholesterol level. They observed a sample average serum cholesterol level of 222 mg/ml in 43 females.

what value would give you the 95% confidence interval for the population mean serum cholesterol level of females?

2. The weight of trout in a fish farm follows the distribution N (200, 502). A trout is randomly selected. What is the probability that its weight is greater than 230g? (a) 0.090 (b) 0.005 (c) 0.500 (d) 0.900

3. The weight of trout in a fish farm follows the distribution N (200, 502). A trout is randomly selected. What is the probability that its weight does not exceed 175g? (a) 0.131 (b) 0.311 (c) 0.113 (d) 0.031

4. Consider the standard normal distribution with mean= 0, and standard deviation= 1. What is the probability that z is between -1.03 and 0.84? (a) 0.486 (b) 0.846 (c) 0.648 (d) 0.684

5. Consider the standard normal distribution with mean= 0, and standard deviation= 1. What is the probability that z is less than 1.1?

(a) 0.648 (b) 0.684 (c) 0.864 (d) 0.486

6. Consider the standard normal distribution with mean= 0, and standard deviation = 1. What is the probability that an outcome z is greater than 2.20? (a) 0.1390 (b) 0.0139 (c) 0.0014 (d) 0.000

7. An investigator wants to assess the usefulness of a certain symptom (S) in the diagnosis of a particular disease (D). In a random sample of 800 patients with the disease, 774 reported having the symptom. In an independent random sample of 1280 subjects without the disease, 17 reported having the symptom. (Hint: The symptom is the test) What is the specificity of using S as a test for D?

(a) 0.987 (b) 0.789 (c) 0.879 (d) 0.500

8. An investigator wants to assess the usefulness of a certain symptom (S) in the diagnosis of a particular disease (D). In a random sample of 800 patients with the disease, 774 reported having the symptom. In an independent random sample of 1280 subjects without the disease, 17 reported having the symptom. (Hint: The symptom is the test) What is the sensitivity of using the symptom (S) as a test for disease (D)?

(a) 0.500 (b) 0.100 (c) 0.750 (d) 0.968