The Nielsen Company conducts survey each year about the use of various media, such as television. A representative sample of adult Americans was surveyed in 2010, and the mean number of minutes per week spent watching television was 576 minutes and sample standard deviation was 60 minutes. An independently selected representative sample of adults was surveyed in 2011, the mean was 646 minutes and sample standard deviation was 80 minutes. Suppose that sample size in each year was 1000. Estimate the difference in the mean spent watching television in 2010 and the mean time spent in 2011 using a 99% confidence interval. Interpret the interval in context.

Acell 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 $45,000 with a standard deviation of $9,200. for a sample of 25 subscribers to plan b, the mean income is $64,300 with a standard deviation of $7,100. at the 0.025 significance level, is it reasonable to conclude the mean income of those selecting plan b is larger? assume unequal population standard deviations. hint: for the calculations, assume the plan a as the first sample. what is the decision rule? (negative amount should be indicated by a minus sign. round your answer to 3 decimal places.) compute the value of the test statistic. (negative amount should be indicated by a minus sign. round your answer to 2 decimal places.) what is your decision regarding h0 ? reject h0 fail to reject h0 compute the p-value. less than 0.01 between 0.01 and 0.025 between 0.025 and 0.05 between 0.05 and 0.10 greater than 0.10