SOLUTION: The distance that students commute to a large college can be modeled by a Normal Distribution where the mean is 7.4 miles and the standard deviation is 2.8 miles. a. The middle

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Question 1197775: The distance that students commute to a large college can be modeled by a Normal Distribution where the mean is 7.4 miles and the standard deviation is 2.8 miles.
a. The middle 91% distance that all students drive is between and miles.
Round these answers to 2 decimal places and enter the lower number first.
b. How likely is it for a randomly-selected student's commute to be more than 16 miles?
Round your answer to 5 decimal places.

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

Hi  
Normal Distribution: µ = 7.4 and σ = 2.8  
Using TI or similarly an inexpensive calculator like an Casio fx-115 ES plus
a. (100 - 91)/2 = .045%  Invnorm(.045) = -1.6954
   7.4 ± (1.6954*2.8) = 7.4 ± 4.7 =   2.7  to 12.1
b. P x > 16) = normcdf(16, 9999, 2.8, 7.4) = .00107  Not Likely
Wish You the Best in your Studies.