A university research team was studying the relationship between idea generation by groups with

and without a moderator. For a random sample of four groups with a moderator, the mean number of

ideas generated per group was 78.0, and the sample standard deviation was 24.4. For a random sample

of five groups without a moderator, the mean number of ideas generated was 63.5 and the sample

standard deviation was 20.2

c) Construct a 98% confidence interval for an unbiased estimate of the difference in the population

means.

d) Interpret your confidence interval. How can you use this confidence interval to decide whether the

means of the two independent populations are statistically significantly different?