Suppose x has a distribution with a mean of 20 and a standar

Suppose x has a distribution with a mean of 20 and a standard deviation of 3. Random samples of size n=36 are drawn.

A. Describe the x distribution and compute the mean and standard deviation of the distribution (answer should be: Normal, u_x=20, õ_x=0.5)

B. Find the z value corresponding to x=19 (answer should be: -2.00)

C. Find P(x<19) (answer should be: 0.0228)

D. Would it be unusual for a random sample of size 36 from the x distribution to have a sample mean less than 19? Explain. (answer should be: Yes, only about 2.3% of all such samples have means less than 19)

Please help me with the formulas to each answer. Thank you

Solution