lesson 8 - measure of central tendency

measure of central tendency

methods used to find the middle or center of a data set

mean

median

mode

three main measures

mean

sum of the numbers then divide by the number of numbers

weighted mean

assigns different weights to each number

median

middle number when dataset is arranged in order (low to high)

mode

most frequently shown number

nominal

ordinal

interval

ratio

type of data

nominal

categories with no specific order (hair colors, names of people)

ordinal

categories with a specific order (education level, likert scale)

interval

numerical scales with equal intervals, no true zero (temperature. time. dates)

ratio

numeric scales with equal intervals and a true zero (height, weight, distance)

even spread (spread)

data looks the same on both sides

skewed (lopsided)

data is bunched up on one side with a few far-out numbers (outliers) on the other side

outliers

far out numbers