A sample of size 21 will be drawn from a population with mean 139 and standard deviation 30. (a) Is it appropriate to use the normal distribution to find probabilities for x? (b) If appropriate find the probability that x will be less than 122. (c) If appropriate find the 80 th percentile of x. It is appropriate to use the normal distribution to find probabilities for x. X 4 The probability that x will be less than 122 is The 80 percentile of x is It is not appropriate to use the normal distribution to find probabilities for x