Question: A Sales and Marketing Management survey included 651 sales managers, and 94% of them said that being a sloppy dresser can make a sales representative's job more difficult. For that same group, 75% said that being an unstylish dresser can make a sales representative's job more difficult.

a. Construct a 90% confidence interval estimate of the percentage of sales managers who say that being a sloppy dresser can make a sales representative's job more difficult.

b. Construct a 90% confidence interval estimate of the percentage of sales managers who say that being an unstylish dresser can make a sales representative's job more difficult.

c. Given that sample proportions naturally vary, can we conclude that when sales managers state reasons for a sales representative's job becoming more difficult, the percentage is higher for sloppy dressing than for unstylish dressing? Why or why not?