I'm doing an on-line stats class and need some clarification.
info as follows:
standard deviation = 6.9centimeters
What is the probability that 1 randomly selected person's height is greater than
I calculated it as:
z= 185-174.5 / 6.9
Using Z-Score table I determined 1.5 = .9332 resulting in 1-.9332 = .0668
So there is a 6.68% probability of 1 person's height being > 185centimeters.
So far so good; however the follow on question ask to find two heights that seperate the top 25% and the bottom 20% of the population.
Question 1: Using x = u + (z * standard deviation) for the top 25%, do I look up .25 on the table (-1.96) and solve for the top 25% height, because I get a number that is < the mean height of 174.5?
x=174.5 + (-1.96 * 6.9) = 160.976
Question 2: Is the process the same for the bottom 20%?
Appreciate any suggestions.