A nationwide survey in 2001 revealed that U. S. grade-school children spend an average of µ = 8.0 hours per week doing homework. The distribution is normal with σ = 2.5. Last year, a sample of n = 100 grade-school children was given the same survey. For this sample, the mean number of homework hours was 7.4. Has there been a significant change in the homework habits of grade-school children? Test with α = .05. What are the 7 steps ?