b) A school district wants to evaluate the effectiveness of a new teaching method for improving students' math scores. They believe the improvement in math scores is normally distributed with o 4 points. A sample of 25 students is randomly selected and their math scores are measured before and after the new teaching method is implemented. The sample standard deviation of the differences in math scores is 5.2 points. Does the school district have evidence to support their assumed standard deviation of 4 points? Use critical values of X6.975 and X3.025 (a 95% window). i) ii) Find the value of the test statistic for this sample and the two critical values. X0.975 = YES x² = Does the school district have evidence to support their assumed standard deviation of 4 points? Circle YES or NO and briefly explain your answer. NO X0.025 =