The desired probability is P(60 < x < 85). First convert this probability statement using the standard random variable, z. Recall the formula for this conversion below, where x is the value that needs to be converted, is the population mean, and a is the population standard deviation. z= X- We found the z value that corresponds to x = 60 to be z = -2. Find the z value that corresponds to x = 85 with mean = 100 and standard deviation = 20. XIF Z 85-100