Question: 1. Items coming off an assembly line have a critical dimension which is represented by a random variable ~ N(10, 0.01). Ten items are selected at random. What is the probability that three or more are within 0.05 of the mean value μ.
2. The result of extensive quality control sampling shows that a certain model of digital watches coming off a production line have accuracy, in seconds per month, that is normally distributed with μ = 5 and σ2 = 300. To achieve a top grade, a watch must have an accuracy within the range of -5 to +10 seconds per month. What is the probability a watch taken from the production line to be tested will achieve top grade? Calculate, using a standardized normal table. Check with the m-function gaussian.