Question 657777: I'm trying to figure out the 2nd part of a 2 part question. I have the initial question answered, but am stumped on the rest...
"The average employee spends a mean of 15 minutes commuting to work each day. Assume that the distribution of commute times is normal with a standard deviation of 8 minutes. What percentage of employees spends more than 30 minutes a day commuting?" <<--for this I came up with a z score of 1.88, % to mean of 46.99, % in tail of 3.01%
This is the part I don't get...
"Only 1.5% of employees spend more time commuting than Mike. How long is his commute? Use the parameters above to answer this question."
I'm drawing a blank about where to even start. Please help!!
Answer by stanbon(75887)   (Show Source):
You can put this solution on YOUR website! "The average employee spends a mean of 15 minutes commuting to work each day. Assume that the distribution of commute times is normal with a standard deviation of 8 minutes. What percentage of employees spends more than 30 minutes a day commuting?" <<--for this I came up with a z score of 1.88,
P(x > 30) = P(z > 1.88) = normalcdf(1.88,100) = 0.0301 or 3.01%
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is is the part I don't get...
"Only 1.5% of employees spend more time commuting than Mike. How long is his commute?
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Find the z-value with a right tail of 1.5%: invNorm(0.885) = 1.2
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Find the x-value associated with z = 1.2
x = z*s +u
x = 1.2*8 + 15
x = 24.6 minutes(time of Mike's commute)
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cheers,
Stan H.
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