(5.7 to 6.5 pounds) was calculated with the usual formula Confidence intervals constructed in this way are symmetrical around the mean; is the mid-point of the confidence interval.

(a) What is the value of the sample mean used to calculate the confidence interval?

(b) What is the margin of error of the confidence interval?

(c) What is the standard error of the estimate?

(d) Calculate a 99% confidence interval for μ.

(e) The sample mean is significantly different from 7.2 pounds at α

= 0.05. Is the difference significant at α = 0.01?