Question

A cell phone company offers two plans to its subscribers. At the time new subscribers sign up, they are asked to provide some demographic information. The mean yearly income for a sample of 40 subscribers to Plan A is $52,500 with a standard deviation of $8,000. For a sample of 25 subscribers to Plan B, the mean income is $63,000 with a standard deviation of $6,900. At the 0.025 significance level, is it reasonable to conclude the mean income of those selecting Plan B is larger? Hint: For the calculations, assume the Plan A as the first sample. The test statistic is . (Negative value should be indicated by a minus sign. Round your answer to 2 decimal places.)

Answer 1