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iris [78.8K]
3 years ago
6

The length of time Y necessary to complete a key operation in the construction of houses has an exponential distribution with me

an 18 hours. The formula C = 100 + 60Y + 3Y2 relates the cost C of completing this operation to the square of the time to completion. The mean of C was found to be found to be 3,124 hours and the variance of C was found to be 28,460,160. How many standard deviations above the mean is 4,000 hours? (Round your answer to two decimal places.)
Mathematics
1 answer:
Butoxors [25]3 years ago
4 0

Answer:

0.16

Step-by-step explanation:

Given that the length of time Y necessary to complete a key operation in the construction of houses has an exponential distribution with mean 18 hours.

The formula for cost of completing this operation is

C = 100 + 60Y + 3Y^2

C has mean 3124

Var(C) = 28,460,160

Std dev (C) = \sqrt{28460160} \\=5334.81

X = 4000 hours

Difference = 4000-3124 = 876

Mean diff/std dev = \frac{876}{5334.81} \\=0.164

i.e.nearly 0.16  standard deviations above the mean is 4,000 hours

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Step-by-step explanation:

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