Hi I need help with this one. Show me the solution.

1. Define the distribution of sample means and a standard error, and explain why we prefer a smaller standard error.

2. A sample is selected from a population with a mean of = 80 and a standard deviation of = 20. The distribution is approximately normal.

a. What is the expected value of M and the standard error for a sample of n = 25 individuals?

b. What is the expected value of M and the standard error for a sample of n = 100 individuals?

c. What value (the expected value of M or the standard error) did change if you changed the sample size?