The lifetimes of lightbulbs that are advertised to last for 5,000 hours are normally distributed with a mean of 5,100 hours and a standard deviation of 200 hours. What is the probability that a bulb lasts longer than the advertised figure?
"X\\sim N(\\mu, \\sigma^2)"
Given "\\mu=5100, \\sigma=200"
"=1-P(Z\\leq\\dfrac{5000-5100}{200})"
"=1-P(Z\\leq-0.5)"
"\\approx0.691462"
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