The number of people contacted at each level of a phone tree can be
represented by f(x) = 3, where x represents the level.
What is x when f(x) - 27?
A. X = 2; At level 2, 27 people will be contacted.
B. x 24; At level 24, 27 people will be contacted.
c. x = 3; At level 3, 27 people will be contacted.
D. X = 9; At level 9,27 people will be contacted.

List x1, x2, x3, x4 where xi is the midpoint endpoint of the five equal intervals used to estimate the area under the curve of f(x) between x = 0 and x = 10.

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?

Abag contains pieces of paper numbered from 5 to 9. a piece of paper is drawn at random. what is the theoretical probability of drawing a number less than 8?