In an experiment to compare two types of feed with respect to weight gain, twenty pigs were randomly divided into two groups, with each group receiving a different feed. After a certain period of time the weight gain (in kg) for each pig was recorded.
Feed A: 71.6 62.7 68.4 66.2 62.5 70.5 63.5 57.2
Feed B: 66.3 70.7 68.4 72.2 69.8 64.8 68.9 68.2 72.8 73.3 61.2 60.4
(a) Is there a significant difference in the mean weight gain for the two types of feed? (a = .05). Use the Pooled T-test.
(b) Conduct the test in (a) using an appropriate confidence interval.