Scores at a local high school on the American College Testing (ACT) college entrance exam follow the normal distribution with a mean of 18 and a standard deviation of 8. A guidance counselor takes a random sample of 20 students and calculates the mean score, x¯. (a) Calculate the mean and standard deviation of the sampling distribution of x¯.
(b) Interpret the standard deviation from part (a).
(c) Find the probability that a sample of 20 students has a mean score of 19.5 or more.

whole numbers.

step-by-step explanation:

we are given the average monthly rainfall (in millimeters) model r(m) for the years 1900-2009 as a function of the month number m.

as we can see m is taken for the number of months for years 1900-2009.

we know that number of months can't be a negative number or decimal number or a fraction.

so, the number of months could be only positive whole numbers.

therefore, whole numbers is more appropriate for the domain of r.

or

c

step-by-step explanation: