PLEASE HELP ASAP, WILL MARK BRAINLIEST!! A local boutique sells water bottles for a set price, plus an additional fee for each letter that customers would like engraved on their water bottle. The pricing for up to 4 engraved letters is shown in the table below.
#of letters 0 1 2 3 4
Total cost 18.99 19.34 19.69 20.04 20.39

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