An amusement park has 15 roller coasters. In how many ways can you choose 10 of the roller coasters to ride during your visit to the park? *

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)