SOLUTION: Suppose that people's heights (in centimeters) are normally distributed, with a mean of 170 and a standard deviation of 5. We find the heights of 90 people. (You may need to use th

Algebra ->  Probability-and-statistics -> SOLUTION: Suppose that people's heights (in centimeters) are normally distributed, with a mean of 170 and a standard deviation of 5. We find the heights of 90 people. (You may need to use th      Log On


   

Question 1201061: Suppose that people's heights (in centimeters) are normally distributed, with a mean of 170 and a standard deviation of 5. We find the heights of 90 people. (You may need to use the standard normal distribution table. Round your answers to the nearest whole number.)
(a) How many would you expect to be between 170 and 180 cm tall?


(b) How many would you expect to be taller than 177 cm?


Answer by Theo(13342) About Me  (Show Source):
You can put this solution on YOUR website!
the probabiliy of heights between 170 and 180 tall is equal to .4772499375.
the probability of heights above 177 is equal to .0807567112.

out of 90 people, .4772499375 * 90 = 43 who are expected to be between 170 and 180 cm tall.

out of 90 people, .0807567112 * 90 = 7 who are expected to be taller than 177 cm.

here are the probabilities using the calculator at https://davidmlane.com/hyperstat/z_table.html





i used the ti-84 plus, which gives you the answer to more decimal places.