Question 8 of 10 In order to solve the following system of equations by addition, which of the
following could you do before adding the equations so that one variable will
be eliminated when you add them?
4x - 2y=7
3.1 - 3y=15
O A. Multiply the top equation by 3 and the bottom equation by 4
O B. Multiply the top equation by 1/3
O c. Multiply the top equation by
-3 and the bottom equation by 2
D. Multiply the top equation by 3 and the bottom equation by 2

Studies show that massage therapy has a variety of health benefits and it is not too expensive. a sample of 12 typical one-hour massage therapy sessions showed an average charge of $58. the population standard deviation for a one-hour session is =$5.55. a. what assumptions about the population should we be willing to make if a margin of error is desired? (select your the population has uniform distribution/ the population is at least approximately normal is required/ the population has no exponential distribution/ no assumptions should be made) b. using 90% confidence, what is the margin of error (to 2 decimals) c. using 99% confidence, what is the margin of error (to 2 decimals)