- This topic has 1 reply, 2 voices, and was last updated 9 months ago by John Moffat.
- You must be logged in to reply to this topic.
ACCA Webinars: How to earn marks in Strategic Professional Exams. Learn more >>
20% off BPP Books for ACCA & CIMA exams - Get BPP Discount Code >>
Can you explain to me how to calculate the upper quartile of normal distribution?
The answer says about some 0.67, which I cannot understand where it came from.
The quartiles are the pints one quarter, two quarters, and three quarters through the distribution.
The upper quartlile is three quarters and the distance between the mean (which is the 2nd quartile) and the upper quartile is 1/4 or 25%.
To get the number of standard deviations that give a probability of 25% or 0.25, we use the normal distribution tables ‘backwards’ in the way I explain in my free lectures, and get 0.67 standard deviations.