SOLUTION: The time taken to complete a statistics final by all students is normally distributed with a mean of 120 minutes and a standard deviation of 10 minutes. a) Find the probability th

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Question 841050: The time taken to complete a statistics final by all students is normally distributed with a mean of 120 minutes and a standard deviation of 10 minutes.
a) Find the probability that a randomly selected sample will take more than 150 minutes to complete the test.
b)Find the probability that the mean time taken to complete the test by a random sample of 16 would be between 122 and 126.

Answer by ewatrrr(24785) About Me  (Show Source):
You can put this solution on YOUR website!
 

Hi,

 mean = 120  and sd = 10

Using TI Calculator

a) Find the probability that a randomly selected sample will take more than 150 minutes to complete the test.

 normalcdf(150, 9999, 100, 10).   

|Note: The 9999 is used as the larger value to be at least 5 standard deviations from the mean.

 b)Find the probability that the mean time taken to complete the test by a random sample of 16 would be between 122 and 126. 

normalcdf(122, 126, 100,10).