1)             As part of a study of the development of the thymus gland, researchers weighted the glands of 41 chick embryos after 14 days of incubation. The mean thymus weight is 21.7 and the standard deviation is 5.6.

b.      Interpret the 95% CI that you just found.

c.       Is 99% CI wider than 95% CI?

d.      Construct an 80% confidence interval for the population mean of thymus weight.

e.      Suppose that the data on the 41 chick embryos are regarded as a pilot study, and that the researchers now wish to design a new study for which they want the standard error of the mean to be only 0.3. How many chick embryos should be involved in the new study?