1.A random sample of 16 group leaders, supervisors, and similar personnel revealed that on the average a person spent 6.5 years on the job before being promoted. The standard deviation of the sample was 2 years. What is the 95% confidence interval for the true population mean?

A.6.46 and 6.54

B.3.17 and 9.83

C.5.43 and 7.57

D.6.20 and 6.70

E.6.32 and 6.88

2.A sample of 500 executives who own their own home revealed 180 planned to sell their homes and retire to Victoria. Develop a 98% confidence interval for the proportion of executives that plan to sell and move to Victoria.

A.30% and 40%

B.31% and 41%

C.28% and 42%

D.29.5% and 40.5%

E.29.3% and 41.3%

3.A consumer group would like to estimate the mean monthly electricity charge for a single family house in July (within $5) using a 95 percent level of confidence. Based on similar studies the standard deviation is estimated to be $20.00. How large a sample is required?

A.61

B.62

C.63

D.64

E.65

4.The Kennel Club wants to estimate the proportion of children that have a dog as a pet. Assume a 95% level of confidence and that the club estimates that 40% of the children have a dog as a pet. If the club wants the estimate to be within 3% of the population proportion, how many children would they need to contact?

A.1978

B.1000

C.1025

D.987

E.897

5What is the critical value at the 0.05 level of significance for a goodness-of-fit test if there are five categories?

A.3.841

B.5.991

C.7.815

D.9.488

6What is our decision regarding the differences between the observed and expected frequencies if the critical value of chi-square is 9.488 and the computed value is 7.79?

A.Do not reject the null hypothesis.

B.Reject the null hypothesis.

C.Start over with a new sample.

D.Too close; reserve judgment.