Amiddle school student studies the amount of time 7th and 8th graders spend playing video games on the weekend by collecting data from a large random sample of students in each grade. her theory is that 7th graders will spend more time playing video games because 8th graders have more difficult classes and must spend more time on school work. in her samples, the mean time spent playing video games on the weekend is 122.4 minutes for 7th graders and 88.6 minutes for 8th graders. assuming there are no outliers or skew, do the results support the student's theory? select from the drop-down menus to correctly complete the statements. since the samples were large and randomly chosen, we can use the samples to understand the populations. because the sample mean for 7th graders is the sample mean for 8th graders, the results support the student's theory.

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