A baseball team plays in a stadium that holds 74000 spectators. With the ticket price at $9 the average attendance has been 30000. When the price dropped to $8, the average attendance rose to 37000. Assume that attendance is linearly related to ticket price. What ticket price would maximize revenue

The management of a supermarket wants to adopt a new promotional policy of giving a free gift to every customer who spends more than a certain amount per visit at this supermarket. the expectation of the management is that after this promotional policy is advertised, the expenditures for all customers at this supermarket will be normally distributed with a mean of $95 and a standard deviation of $20. if the management wants to give free gifts to at most 10% of the customers, what should the amount be above which a customer would receive a free gift?