a. For a sample with a standard deviation of s = 6, a score of X = 30 corresponds to z = 21.50. What is the sample mean? b. For a sample with a mean of M = 63, a score of X = 54 corresponds to z =...

a. For a sample with a standard deviation of s = 6, a score of X = 30 corresponds to z = 21.50. What is the sample mean?

b. For a sample with a mean of M = 63, a score of X = 54 corresponds to z = 20.75. What is the sample standard deviation?