In a large population of adults, the mean IQ is 116 with a standard deviation of 18. Suppose 40 adults are randomly selected for a market research campaign. (Round all answers to 4 decimal places, if needed.)
(a) The distribution of IQ is approximately normal is exactly normal may or may not be normal is certainly skewed.
(b) The distribution of the sample mean IQ is approximately normal exactly normal not normal left-skewed right-skewed with a mean of ? and a standard deviation of ?.
(c) The probability that the sample mean IQ is less than 112 is .
(d) The probability that the sample mean IQ is greater than 112 is .
(e) The probability that the sample mean IQ is between 112 and 122 is .
