Z-Score for Quartiles

H

HerdingDogRescuer

New member
Joined
Dec 31, 2015
Messages
1
For the standard normal distribution, what z-score corresponds with the second quartile?

My practice quiz says 0.00 and I don't know why.

They had a similar question as well:

For the standard normal distribution, what z-score corresponds with the first quartile?

The answer for this was -0.67, found by locating the value closest to 0.25 on the table which is 0.2486, then finding the z value for this. which is 0.67. As this is below the mean of 0 I assume that's why it's negative.

Now for the second quartile question I thought it would be the same thing. Find the closest value to 0.5 which is 0.4990 which is a z of 3.9, but they say 0.0. So I am lost.

Can anyone help please?
 
HerdingDogRescuer said:
For the standard normal distribution, what z-score corresponds with the second quartile?

My practice quiz says 0.00 and I don't know why.

They had a similar question as well:

For the standard normal distribution, what z-score corresponds with the first quartile?

The answer for this was -0.67, found by locating the value closest to 0.25 on the table which is 0.2486, then finding the z value for this. which is 0.67. As this is below the mean of 0 I assume that's why it's negative.

Now for the second quartile question I thought it would be the same thing. Find the closest value to 0.5 which is 0.4990 which is a z of 3.9, but they say 0.0. So I am lost.

Can anyone help please?
Click to expand...
You seem confused about just what a quartile is. You might want to look at
https://en.wikipedia.org/wiki/Quartile
 
HerdingDogRescuer said:
For the standard normal distribution, what z-score corresponds with the second quartile?

My practice quiz says 0.00 and I don't know why.

They had a similar question as well:

For the standard normal distribution, what z-score corresponds with the first quartile?

The answer for this was -0.67, found by locating the value closest to 0.25 on the table which is 0.2486, then finding the z value for this. which is 0.67. As this is below the mean of 0 I assume that's why it's negative.

Now for the second quartile question I thought it would be the same thing. Find the closest value to 0.5 which is 0.4990 which is a z of 3.9, but they say 0.0. So I am lost.

Can anyone help please?
Click to expand...

The second quartile is where 50% of the data would lie below. In a normal distribution this is the same value as the mean. What is the mean of the Z distribution?
 
You must log in or register to reply here.
Top