Music students often don’t evaluate their own performances accurately. can small-group discussions ?
a) the subjects were 29 students preparing for the end-of-semester performance that is an important part of their grade.
b) the 15 students in one group each videotaped a practice performance, evaluated it themselves, and then discussed the tape with a small group of other students.
c) the remaining 14 students watched and evaluated their tapes alone.
d) at the end of the semester, the discussion-group students evaluated their final performance more accurately

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