01:830:200 Lecture Notes - Lecture 2: Interquartile Range, Quartile, Percentile

• School: Rutgers University
• Department: Psychology
• Course: 01:830:200
• Professor: Dr. Kilianski

Document Summary

Percentile : a point on a distribution below which a given percentage of scores fall. Ex. if a score is in the 95th percentile, 95% of scores are below it. Quartile : divide a distribution into quarters. Interquartile range describes the middle 50% of the distribution, excluding the top/bottom 25% Quartile deviation: when the iqr is divided in half; q should be equal to. Of st. dev. when the distribution is normal. Decile : divides a distribution into tenths. Positive skew: mean is greater than median. Negative skew : mean is lesser than median. Standard deviation : a measure of variability that indicates by how much all the scores in a distribution typically deviate or vary from the mean [can"t be more than r] Average distance from the mean; greater it is, more variability. Raw score - mean = x x^2. Kurtosis : how peaked or flat a bell curve is.