1. In a certain manufacturing process, lengths (in cm) of bolts are normally distributed with µ = 5.4 and σ = .6. Find the probability that a bolt selected at random has a length greater than 5.832 cm.
2. As measured with the Stanford-Binet Intelligence Scale, IQ scores are normally distributed with mean 100 and standard deviation 16.
(a) What percent of the population has an IQ score of 140 or more?
(b) Find the 90th percentile of IQ scores.