Students from three high schools write a standardised exam at the end of the school year. The results are given below. The school board is interested in determining if there is a difference in the mean grades at the schools. Answer the following questions: Central lHigh Plains lBridgewood 57 '46 I68 56 '54 '75 73 '56 '90 61 I49 I68 53 '60 '75 55 '57 I60 63 '73 '83 47 l '66 | |75 a) What is the critical value at the 0.05 significance level? For full marks your answer should be accurate to at least two decimal places. lCritical value: - I b) What is the test statistic? For full marks your answer should be accurate to at least two decimal places. ltest statistic: - l 0) Can we conclude there is a difference in mean test scores for the three schools? 0 Yes, because the test statistic is greater than the critical value 0 Yes, because the test statistic is less than the critical value 0 No, because the test statistic is greater than the critical value 0 No, because the test statistic is less than the critical value