A survey of 25 grocery stores revealed that the average price of a gallon of milk was $2.98 with a standard error of $0.10. If 90% and 95% confidence intervals are developed to estimate the true cost of a gallon of milk, what similarities would they have?
A) Point estimates
B) t-statistics
C) Standard errors
D) Both a and c

Question

Quizplus · Accepted Answer

Both 90% and 95% confidence intervals would have the same point estimate, which is the sample mean of $2.98 for the price of a gallon of milk. Additionally, both confidence intervals would use a t-statistic to calculate the interval limits due to the small sample size. Finally, both intervals would have the same standard error of $0.10 since it is a characteristic of the sample and not affected by the level of confidence chosen. Therefore, choice D (Both a and c) is the best answer.

A Survey of 25 Grocery Stores Revealed That the Average