1/5
Looks like no tags are added yet.
Name | Mastery | Learn | Test | Matching | Spaced | Call with Kai |
|---|
No analytics yet
Send a link to your students to track their progress
Normal Distribution: Bell Curve Distribution (Normally Distributed Variable)
When the mode, mean and median are roughly the same. (50% more and 50% less)
The Empirical Rule(s)
3 and can only be applied to a bell curve (normally distributed variable). YOU MUST BE EXPLICITLY TOLD THERE IS A BELL CURVE TO SOLVE USING THESE RULES, IF NOT, YOU CANNOT SOLVE.
1 SD
68%
2 SD
95%
3 SD
99.7%
Examples
EX 1: mean is 120. 1 SD = 20 points. What % of the observations are between 100 and 140? Supposed the sample size is 500.
Answer: 100-140 are between 68% (1 SD).
EX 2: How many observations are between 100-140? .68 × 500 = 340.
EX 3: Quantify 145: 100 - 68 = 32 (half and half: bell curve). 32/2 = top 16%
EX 4: 165? 100 - 95 = 5. 5/2 = top 2.5%