Question

Suppose x has a distribution with a mean of 90 and a standard deviation of 20. Random samples of size n = 64 are drawn. (a) Describe the distribution. has an approximately normal distribution. has a normal distribution. has a geometric distribution. has a binomial distribution. has an unknown distribution. has a Poisson distribution. Compute the mean and standard deviation of the distribution. (For each answer, enter a number.) = mu sub x bar = = sigma sub x bar = (b) Find the z value corresponding to = 85. (Enter an exact number.) z = (c) Find P( < 85). (Enter a number. Round your answer to four decimal places.) P( < 85) = P(x bar < 85) (d) Would it be unusual for a random sample of size 64 from the x distribution to have a sample mean less than 85? Explain. No, it would not be unusual because more than 5% of all such samples have means less than 85. No, it would not be unusual because less than 5% of all such samples have means less than 85. Yes, it would be unusual because more than 5% of all such samples have means less than 85. Yes, it would be unusual because less than 5% of all such samples have means less than 85.

Answer 1