Probability and Statistics Pretest

What is the sample size required to estimate the population mean with a 95% confidence level and a margin of error of 2?

• 1

• 50

• 10

• 100

What is the probability of rolling a 3 on a fair six-sided die?

• 1/2

• 1/3

• 1/4

• 1/6

The average senior high school has 258 students with a standard deviation of 36. If a random sample of 32 senior high schools is selected, what is the probability that the number of students enrolled is greater than 205?

• 0.2823

• 0.2794

• 0.2206

• 0.2177

What is the mean of a sample with numbers 2, 5, 8, and 12?

• 9.25

• 9.00

• 6.75

• 5.40

A population consists of the five measurements 2, 6, 8, 0, and 1. Suppose samples of size 4 are drawn from this population. What is the variance of the sampling distribution of the sample means?

• 0.73

• 0.78

• 0.83

• 0.88

What is the point estimate of the population mean for the given samples: 18.5, 19.2, 16.8, 19.1, and 22.3?

• 20.31

• 19.75

• 19.18

• 18.98

What is the confidence coefficient t when n = 12 for the 90% confidence interval?

• 1.782

• 1.796

• 2.201

• 3.106

What is the confidence coefficient z for the 95% confidence interval?

• 1.65

• 1.96

• 2.58

• 3.00

What is the margin of error E of the 99% confidence interval estimate of the population mean u when s = 10 and n = 25. (s for standard deviation; n for sample size)

• 3.41

• 3.42

• 4.12

• 5.59

A study of 36 horses showed that they could walk an average of 5.4 kilometers per hour. The standard deviation is 0.84. Find the 95% confidence interval of the true mean.

• 5.13 < u < 5.67

• 5.17 < u < 5.63

• 5.04 < u < 5.76

• 5.08 < u < 5.72