7.3.1 - Video Example: Middle 80% of the z Distribution
Question: What z scores separate the middle 80% of the z distribution from the outer 20%?
Steps
- On a PC: from the menu select STATISTICS > Distribution Plot
On a Mac: from the menu select Statistics > Probability Distributions > Distribution Plot - Select Display Probability (Note: The default is the standard normal distribution)
- Select A specified probability
- Select Equal tails
- For Probability enter 0.20
Video Walkthrough