In Research on Cell Phone Use by Teenagers,it Was Found

Essay

In research on cell phone use by teenagers,it was found that the average connect time for a call was at least 15 minutes.Social psychologists feel that this study understated the time.To determine this claim,cell phone bills for 15 teenagers were evaluated.On average,the time spent was 18.5 minutes,with a sample standard deviation of four minutes.(Assume a normal distribution. )What is the critical value for α = .001 to test the hypotheses.Determine whether the null hypothesis can be rejected at this level.