[zetablue1]

I have the following equation to solve:

We are going to try to apply the Standard Normal Distribution.

The average IQ for people is 100. The standard deviation is 16. Since I can't give you an IQ test we're going to make one up for each of you.

We'll do that as follows: take your age, divide by 2 and add 100. For this response use that value as your IQ, and determine what percentage of people would have a higher IQ. (e.g. Age = 40 y. Then you would determine percentage of people who have IQ greater than 120.)

This is what I came up with. Can you tell me if this is correct and if not where am I going wrong?

The IQ I am solving for is 44/2 + 100 = 122

122-100/16 = 22/16= 1.375

P(x>122) = P(z>1.375)
P(z>1.375 = 1-P(z<1.375)
= 1-0.9147 = 0.0853 = 8.5% people have an IQ of 122 or higher

[Unknown008]

This seems good to me. Well done! :)

[morgaine300]

P(x>122) = P(z>1.375)
P(z>1.375 = 1-P(z<1.375)
= 1-0.9147 = 0.0853 = 8.5% people have an IQ of 122 or higher

Are you supposed to be rounding 1.375 down to 1.37 for some reason? The .9147 is for 1.37.

(And do you not have a tail chart so you don't have to do all that re-arranging?)

[Unknown008]

I don't know what is his table for the distribution. Do all of them contain values of z of up to 4 dp and higher or are there some with only three dp?

[morgaine300]

I've seen about three different types of charts. The first is the kind I originally learned from. The second is the kind the current book in use at my school uses. (Same book I had but newer version.) That one doesn't do detail after 3.0. That looks to be the kind OP used. I can't find an example of a tail chart. It's like the opposite of the second chart so you don't have to do the subtracting.

http://www.science.mcmaster.ca/psych...e/z-table2.jpg
http://business.statistics.sweb.cz/normal01.jpg

[zetablue1]

I've seen about three different types of charts. The first is the kind I originally learned from. The second is the kind the current book in use at my school uses. (Same book I had but newer version.) That one doesn't do detail after 3.0. That looks to be the kind OP used. I can't find an example of a tail chart. It's like the opposite of the second chart so you don't have to do the subtracting.

http://www.science.mcmaster.ca/psych...e/z-table2.jpg
http://business.statistics.sweb.cz/normal01.jpg

Thanks!

[Unknown008]

I found that site. The tail chart is named 't chart' here

Distribution Tables

[morgaine300]

t chart is a different thing, though a t chart does usually seem to be a tail chart. Z is on there - it's the infinity at the bottom.