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?

Transcribed Image Text:

Sample Mean Sample Standard Deviation Ten Years Ago 73 25 This Year 63 28