Problem 3

Part A: An experimental diet to induce weight loss was followed for one week by a randomly selected group of 5 students with the following results.

Student	Loss in Pounds
1	2.1
2	2.7
3	0.8
4	2.2
5	1.2

Find a point estimate for the average weight loss in pounds after one week on this diet. Is this an unbiased estimate of the population mean? Explain.

Part B: A consumer testing organization reports that at 99% confidence that the true average content of the drinks is between 10.8 to 11.4 ounces. The sample revealed an average content is 11.1 ounces. Assuming the standard deviation of the population is 1.28, determine the size of the sample.

Part C: In a sample of 2000 systems sold, 30 systems were defective. Determine a 90% confidence interval for the percentage of defective systems.

Part A

45	A point estimate for the average weight loss is ________________ . The true mean of the population The standard deviation of the population The sample mean for the selected employees None of the above
46	The point estimate for the average weight loss after one week of diet equals to ______________ pounds. 1.64 8.20 2.60 0.44
47	The point estimate based on the sample data ______________ . Is a biased estimate of the population mean because its value is different from the population mean Is biased estimate of the population mean because all sample values are positive Is unbiased estimate of the population mean because its value is different from the population mean Is unbiased estimate of the population mean because the expected value of the sample mean equals the population mean Part B
48	The margin of error equals to ______________ ounces. 0.6 0.3 10.8 11.4
49	The z-score should be found for alpha/2 = __________ . 0.01 0.005 0.025 0.495
50	For the given margin of error, the sample size equals about ________ . 133 110 121 215 Part C
51	The sample proportion equals to ____________ . 0.0035 0.0092 0.0208 0.0150
52	The standard deviation of the sample proportion equals to ____________ . 0.0092 0.0035 0.0150 0.0208
53 The 90% confidence interval for the percentage of defective systems is the interval ____________ . From 0.35% to 1.50% From 1.50% to 2.08% From 0.92% to 2.08% From 0.92% to 1.50%