Steve's average golf score at his local course is 93.6 from a random sample of 34 rounds of golf. assume that the population standard deviation for his golf score is 4.2. the margin of error for a 95% confidence interval around this sample mean is

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?