MCQs: Hypothesis Testing & Confidence Interval

1. Katherine Tao, Director of Marketing Research, is evaluating consumer acceptance of a new toothpaste package. Her staff reports that 17% of a random sample of 200 households prefers the new package to all other package designs. If Katherine concludes that 17% of all households prefer the new package, she is using a _______.

A. a point estimate
B. a range estimate
C. a statistical parameter
D. an interval estimate
E. an exact estimate

2. The z value associated with a two sided 95% confidence interval is _______.

A.1.28
B. 1.645
C. 1.96
D. 2.575
E. 2.33

3. Suppose a random sample of 36 is selected from a population with a standard deviation of 12. If the sample mean is 98, the 99% confidence interval to estimate the population mean is _______.

A. 94.08 to 101.92
B. 92.85 to 103.15
C. 97.35 to 98.65
D. 93.34 to 102.66
E. 90.20 to 105.00

4. Jack Devereaux, VP of Human Resources of Allied First Banks (AFB), is reviewing the employee training programs of AFB banks. His staff randomly selected personnel files for 100 tellers in the Southwest Region and determined that their mean training time was 25 hours. Assume that the population standard deviation is 5 hours. The 88% confidence interval for the population mean of training times is ________.

A. 17.25 to 32.75
B. 24.23 to 25.78
C. 24.42 to 25.59
D. 19.15 to 30.85
E. 21.00 t0 32.00

5. The table t value associated with the upper 5% of the t distribution and 12 degrees of freedom is _______.
A. 2.179
B. 1.782
C. 1.356
D. 3.055
E. 3.330

6. A researcher wants to determine the sample size necessary to adequately conduct a study to estimate the population mean to within 5 points. The range of population values is 80 and the researcher plans to use a 90% level of confidence. The sample size should be at least _______.

A. 44
B. 62
C. 216
D.692
E.700

7. Consider the following null and alternative hypotheses.
Ho: μ ≤ 67
Ha: μ > 67
These hypotheses _______________.

A. indicate a one-tailed test with a rejection area in the right tail
B. indicate a one-tailed test with a rejection area in the left tail
C. indicate a two-tailed test
D. are established incorrectly
E. are not mutually exclusive

8. Consider the following null and alternative hypotheses.
Ho: μ = 67
Ha: μ ≠ 67
These hypotheses ______________.

A. indicate a one-tailed test with a rejection area in the right tail
B. indicate a ne-tailed test with a rejection area in the left tail
C. indicate a two-tailed test
D. are established incorrectly
E. are not mutually exclusive

9. Suppose the alternative hypothesis in a hypothesis test is: "the population mean is less than 60". If the sample size is 50 and alpha =.05, the critical value of z is _______.

A. 1.645
B.-1.645
C. 1.96
D.-1.96
E. 2.05

10. In a two-tailed hypothesis about a population mean with a sample size of 100 and α = 0.05, the rejection region would be _______.
A. z > 1.64
B. z > 1 96
C. z < -1.96 and z > 1.96
D .z < -1.64 and z > 1.64
E. z < -2.33 and z > 2.33