Red Meat, continued Refer to Exercise 8.77. The researcher selects two groups of 400...

Red Meat, continued Refer to Exercise 8.77. The researcher selects two groups of 400 subjects each and collects the following sample information on the annual beef consumption now and 10 years ago:

a. The researcher would like to show that per-capita beef consumption has decreased in the last 10 years, so she needs to show that the difference in the averages is greater than 0. Find a 99% lower confidence bound for the difference in the average per-capita beef consumptions for the two groups.

b. What conclusions can the researcher draw using the confidence bound from part a?

Reference:

Less Red Meat! As Americans become more conscious of the importance of good nutrition, some researchers believe that we may be eating less red meat. To test this theory, a researcher decides to select hospital nutritional records for subjects surveyed 10years ago and to compare the average amount of beef consumed per year to the amounts consumed by an equal number of subjects she will interview this year. She knows that the amount of beef consumed annually by Americans ranges from 0 to approximately 104 pounds. How many subjects should the researcher select for each group if she wishes to estimate the difference in the average annual per-capita beef consumption correct to within 5 pounds with 99% confidence?