1) In a standard normal distribution, what fraction of the data is between the mean and 0.6?
2) In a standard normal distribution, what percent of the data is between -0.4 and 0.4?
3) In a standard normal distribution, what percent of the data is between two and three standard deviations below the mean?
All help is appreciated :)
1) Here...I'm assuming that .06 is a z score
The value associated with a z score of .06 = .5239
The mean will have a z score of 0 .....of course.....the value associated with the mean = .5000
So.....the percent of data falling between .5000 and .5239 =
[ .5239 - .5000] = ..0239 ≈ 2.39%
Nice I got the first one correct, although I did it a little differently than you did.
I have a chart here and for 0.6 it says that 0.6 = .2257. Does that change anything? I am to use the chart that I have.
I made the same mistake originally
z score for 0.6 = .7257
But we want the score associated with .06
This is .5239
2) In a standard normal distribution, what percent of the data is between -0.4 and 0.4?
The z score value associated with .0.4 is .6554
The z score value associated with -.0.4 is .3446
So.....the percent of data falling between these is [ .6554 - .3446] = .3108 = 31.08%
CORRECTED ANSWER !!!!
3) In a standard normal distribution, what percent of the data is between two and three standard deviations below the mean?
The percent of data falling between two and three SDs below the mean is the same percent of data falling between two and three SDs above the mean
The percent = 1.7% between 2 and 2.5 SDs above the mean plus .5 % between 2.5 and 3 SDs above the mean
So....the total % = [ 1.7 + .5 ] % = 2.2%