Suppose x has a distribution with a mean of 50 and a standard deviation of 20. Random samples of size n = 64 are drawn. (a) Describe the x distribution and compute the mean and standard deviation of the distribution. x has a normal distribution with mean = and standard deviation or = (b) Find the z value corresponding to x = 55. (c) Find P(x < 55). (Round your answer to four decimal places.) P(x < 55) = (d) Would it be unusual for a random sample of size 64 from the x distribution to have a sample mean less than 55? Explain. No, it would not be unusual because more than 5% of all such samples have means less than 55. Yes, it would be unusual because less than 5% of all such samples have means less than 55. • No, it would not be unusual because less than 5% of all such samples have means less than 55. Yes, it would be unusual because more than 5% of all such samples have means less than 55.