20 points to whoever helps me:(

A simple random sample of 25 vitamin tablets is obtained, and the potassium content of each tablet is measured. The sample has a standard deviation of 3.7 mg. Use a 0.05 significance level to test the claim that the potassium content of the vitamin tablets has a standard deviation equal to 3.2 mg. Find the critical value(s) needed to test the claim.
a. 12.401, 39.364
b. 13.848, 36.415
c. 33.196
d. 36.415

You are a clerk at convenience store. a customer owes 11.69 for a bag of potatoes chips. she gives you a five dollar bill. how much change should the customer receive?

Ascientist places 24 cells in a petri dish. she knows the cells grow at an exponential rate, doubling in number every hour. how long will it take (in hours) for there to be 1100 cells in the dish? time to 1100 cells: 5.51832530 hours how long will it take to reach 110 cells? time to 110 cells : 2.1963972 hours what is the average rate of change in the number of cells between 9 hours and 11 hours? average rate of change: cells per hour what is the instantaneous rate of change after 7 hours? instantaneous rate of change: cells per hour note: you can earn partial credit on this problem.

Agrid shows the positions of a subway stop and your house. the subway stop is located at (-5,2) and your house is located at (-9,9). what is the distance, to the nearest unit, between your house and the subway stop?