Ordinary corn doesn’t have as much of the amino acid lysine as animals need in their feed. Plant scientists have developed varieties of corn that have increased amounts of lysine. In a test of the quality of high-lysine corn as animal feed, an experimental group of 20 one-day-old chicks ate a ration containing the new corn. A control group of another 20 chicks received a ration that was identical except that it contained normal corn. The weight gains after 21 days are given below.
(a) Let ì1 = mean weight gain for the control (normal corn) group and let ì2 = mean weight gain for the experimental (high lysine) group. Is the high lysine corn effective in increasing weight gain? Carry out a hypothesis test involving ì1 !ì2 to find out.
|If you find that the high lysine corn does yield higher weight gains, estimate the mean
extra weight gain with a 95% confidence interval for ì1 !ì2. Interpret.
Control and Experimental Factor Tables