# A random variable is binomially distributed

1. A random variable is binomially distributed with n = 16 and π = .40. The expected value and standard deviation of the variables are:

A. 2.00 and 1.24

B. 4.80 and 4.00

C. 6.40 and 1.96

D. 2.00 and 1.20

2. If σ = 12, find the sample size to estimate the mean with an error of ± 4 and 95 percent confidence (rounded to the next higher integer).

A. 75

B. 35

C. 58

D. 113

3. The owner of Torpid Oaks B&B wanted to know the average distance its guests had traveled. A random sample of 16 guests showed a mean distance of 85 miles with a standard deviation of 32 miles. The 90 percent confidence interval (in miles) for the mean is approximately:

A. (71.0, 99.0)

B. (71.8, 98.2)

C. (74.3, 95.7)

D. (68.7, 103.2)