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Question 10The physical plant at the main campus of a large state university recieves daily requests to replace florecentlightbulbs. The distribution of the number of daily requests is bell-shaped and has a mean of 56 and a standarddeviation of 11. Using the Empirical Rule rule, what is the approximate percentage of lightbulb replacementrequests numbering between 56 and 89?Do not enter the percent symbol.ans =%

User Saly
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16 votes

We know that the empirical rule states that 99.7% of the area is in the interval:


(\mu-3\sigma,\mu+3\sigma)

In this case we notice that we are looking at the interval (56,89) in a normal distribution with mean 56 and standard deviation 11, which means that we area in the interval:


(\mu,\mu+3\sigma)

which means that we have half the area of the interval mentioned before. Therefore, the approximate percentage between 56 and 89 is 49.85%

User Raghav Rach
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