A marketing firm is doing research for an Internet-based company. It wants to appeal to the age group of people who spend the most money online. The company wants to know if there is a difference in the mean amount of money people spend per month on Internet purchases depending on their age bracket. The marketing firm looked at two age groups, 18-24 years and 25-30 years, and collected the data shown in the following table. Let Population 1 be the amount of money spent per month on Internet purchases by people in the 18-24 age bracket and Population 2 be the amount of money spent per month on Internet purchases by people in the 25-30 age bracket. Assume that the population variances are not the same. Internet Spending per Month
18-24 Years25-30 Years
Mean Amount Spent56.8143.19
Standard Deviation16.9512.83
Sample Size2319
Step 1 of 2:
Construct a 95% confidence interval for the true difference between the mean amounts of money per month that people in these two age groups spend on Internet purchases. Round the endpoints of the interval to two decimal places, if necessary.
Interpret the confidence interval (0.29,14.27)(0.29,14.27) obtained in Step 1. and why?