question problems attached

Where appropriate, show work and the logical path to your answer.

Consider the following data: x1 = 20, x2 = 5, x3 = 10, x4 = 13, x5 = 17, x6 = 18.

1. Compute the sample variance of the above data.

A. 2 B. ≈ 5.63 C. 20 D. ≈ 31.7 E. other value

2. Compute the range of the above data.

A. 2 B. 6 C. 8 D. 15 E. other value

3. Suppose a simple random sample of size 20 from a normal population yields observed statistics of ̄x = 31.3 and

s = 5.8. Find a 99% confidence interval for the population mean μ.

A. [28.02, 34.58] B. [28.01, 34.59] C. [27.61, 34.59] D. [27.59, 35.01] E. other value

4. Suppose that of 250 high school seniors polled 150 of them say they plan to go to college. Find a (two-sided)

98% confidence interval for number of high school seniors who plan to go college.

A. [.549, .651] B. [.539, .661] C. [.528, .672] D. [.520, .680]

5. How many people would you have to poll to be 90% sure that your margin of error will be less than 2%?

A. 1,702 B. 2,401 C. 3,394 D. 4,161 E. other value