A research group is on a college campus and is conducting a survey regarding the coffee consumption of college students in America. Which of the following techniques would probably produce a sample that is most representative of the population? Survey a randomly selected group of students that walk into the campus coffee shop.
Survey all students whose last name begins with R.
Survey a randomly selected group of students from an all-campus event.
Survey all students that attend their early morning class on a certain morning.

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