Discussion:
Q: Stonefield Homes is developing 2 parcels near Minneapolis, MN. In order to test different advertising approached, they use different media to reach potential buyers. The mean annual family income for 75 people making inquiries at the first development is $150,000, with a standard deviation of $40,000. A corresponding sample of 120 people at the second development had a mean of $180,000, with a standard deviation of $30,000. At the .05 significance level, can Stonefield conclude that the population means are different?