Which of these is an example of a random sample?

A.
A phone plan company surveys people on the beach to see how well they are receiving service, and uses this information in future advertising.

B.
Customers buying a new cell phone are surveyed about cell phone plans.

C.
Every twentieth caller to an independent radio station receives tickets to a concert.

D.
A phone survey is conducted using twenty names randomly taken from the phone book.

Can (3,5 and square root 34) be sides on a right triangle?

What are the coordinates of the point that is 1/3 of the way from a to b? a (2,-3) b (2,6)

Tom is the deli manager at a grocery store. he needs to schedule employee to staff the deli department for no more that 260 person-hours per week. tom has one part-time employee who works 20 person-hours per week. each full-time employee works 40 person-hours per week. write and inequality to determine n, the number of full-time employees tom may schedule, so that his employees work on more than 260 person-hours per week. graph the solution set to this inequality.