SOLUTION: The police department of a major city has found that the average height of their 1,250 officers is 71 inches with a standard deviation of 2.3 inches. a. How many officers are at

Algebra ->  Probability-and-statistics -> SOLUTION: The police department of a major city has found that the average height of their 1,250 officers is 71 inches with a standard deviation of 2.3 inches. a. How many officers are at      Log On


   

Question 905925: The police department of a major city has found that the average height of their 1,250 officers is 71 inches with a standard deviation of 2.3 inches.
a. How many officers are at least 75 inches tall?
b. What percent of officers are between 65 and 72 inches tall?
c. The top 10% of the officers in terms of height also make higher salaries than the shorter officers. How tall does an officer have to be to get in that top 10% group? (I.e. what is the height marking off the top 10 percent?)
Answer by ewatrrr(24785) About Me  (Show Source):
You can put this solution on YOUR website!
 

Hi,

TI syntax is normalcdf(smaller, larger, µ, σ).

Note: The -9999 is used as the smaller value(if unknown) to be at least 5 standard deviations from the mean.

0r

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

a. P (x ≥ 75) = normalcdf(75, 9999, 71, 2.3).

b. normalcdf(65, 72, 71, 2.3).

c. invNOrm(.90) = (X-71)/2.3

2.3invNOrm(.90) + 71 = X, How tall an officer has to be to get in that top 10% group