Question

For all hypothesis tests, use both the critical value/rejection region and p-value (separate and label each method) and show each of the 5 steps explicitly.

Volunteers who had developed a cold within the previous 24 hours were randomized to take either placebo lozenges or zinc every 2 to 3 hours until their cold symptoms were gone. 20 participants took placebo lozenges and 25 participants took zinc lozenges. For the placebo group, the mean overall duration of symptoms was 8.1 days and the standard deviation was 1.8 days. The mean overall duration of symptoms for the zinc lozenges group was 4.5 days with a standard deviation of 1.6 days. We believe that the mean duration of symptoms for those taking the placebo lozenges will be greater than the mean duration of symptoms for those taking zinc. Construct a 95% Confidence interval for the difference of the two means.

****Let population 1 be the placebo lozenges group and population 2 be the zinc lozenges group.

Answer 1