11. (10 pts total) One measure of quality and customersatisfaction is repeat business. A supplier of paper used forcomputer printouts obtained a random sample of 80 customer accountsfrom 2014 and found that 40 of these had placed more than one orderduring 2014. A similar survey conducted at the end of the 2015revealed that 40 of 58 customers ordered again during 2015. (a) (8pts) Do these data support the contention that there has been anincrease in the proportion of repeat business from 2014 to 2015? Doa statistical test to see whether this contention is true (statethe null and alternative hypotheses). Make your decision based on alevel of significance of ? = 0.05. Make sure you state the value ofdf if it is relevant. (b) (2 pts) Based on your answer to part (a),to what type of error are you now subject to? (Type I or TypeII?)
