Completion time (from start to finish)of a building remodeling project is normally distributed with a mean of 200 work-days and a standard deviation of 10 work-days.The probability that the project will be completed within 185 work-days is ______.
A)0.0668
B)0.4332
C)0.5000
D)0.9332
E)0.9950

Question

Quizplus · Accepted Answer

To find the probability that the project will be completed within 185 work-days, we use the Z-score formula: Z = (X - μ) / σ, where X is the value (185 days), μ is the mean (200 days), and σ is the standard deviation (10 days). Plugging in the values, we get Z = (185 - 200) / 10 = -15 / 10 = -1.5. Looking up the Z-score of -1.5 in the standard normal distribution table gives us a probability of approximately 0.0668.

Completion Time (From Start to Finish)of a Building Remodeling Project