Ateacher wants to know whether the boys in the entire school prefer watching television or playing outdoor games after school. the teacher draws a random sample from the following groups: all school teachers all students on the football team all boys in each grade all students in each grade which of the following groups best represents the population from which she should take a random sample to get the best results for her survey?

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?