1)When a confidence interval for a population mean is constructed from sample data,

A.we can conclude that the population mean is in the interval.

B.we can conclude that the population mean is not in the interval.

C.we can conclude, with a stated level of confidence, that the population mean is in the interval.

D.we cannot make any inferences

2)A survey of 144 retail stores revealed that the average price of a DVD was $375 with a standard error of $20. What is the 95% confidence interval to estimate the true cost of the DVD?

3)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 30% 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?