For the following problem, use the 68-95-99.7 Rule to approximate the probability rather than using technology to find the values more precisely. Although controversial and the subject of some recent law suits, some human resource departments administer standard IQ tests to all employees. One IQ test's scores are well modeled by a Normal model with mean 100 and standard deviation 20. If the applicant pool is well modeled by this distribution, what cutoff value would separate a randomly selected applicant into the following regions? a) the highest 50% b) the highest 16% c) the lowest 2.5% d) the middle 68%