Marc's elevation decreases by 350 meters as he rides his bike down to the bottom of a hill. he did the ride in 5 equal stages. how much did marc's elevation change during each stage? (i would prefer if you didn't tell me the answer, just tell me if i should divide, multiply, etc. i forgot : /)

A. find the power of the test, when the null hypothesis assumes a population mean of mu = 450, with a population standard deviation of 156, the sample size is 5 and the true mean is 638.47 with confidence intervals of 95 b. find the power of the test, when the null hypothesis assumes a population mean of mu = 644, with a population standard deviation of 174, the sample size is 3 and the true mean is 744.04 with confidence intervals of 95% c. find the power of the test, when the null hypothesis assumes a population mean of mu = 510, with a population standard deviation of 126, the sample size is 10 and the true mean is 529.44 with confidence intervals of 95