7: Measures Of Central Tendency

Front 1

three major properties or characteristics which describe a set of data pertaining to some variable of interest

Back 1

1. location
2. dispersion
3. shape

Front 2

if these properties (location, dispersion, shape) are computed from the observations associated with a sample of data, they are called...

Back 2

statistics

Front 3

if these properties (location, dispersion, shape) are computed from an entire population of data, they are called...

Back 3

parameters

Front 4

three typical measures of location

Back 4

1. sample mean
2. sample median
3. sample mode

Front 5

samples can have the same __________ and the same _______, yet have different measures of _________

Back 5

samples can have the same level of dispersion and the same shape, yet have different measures of location

Front 6

sample mean

Back 6

• commonly acts as a balancing point, where observations which are larger balance out observations which are smaller
  
• based on every observation so extreme values in the sample affect the sample mean

Front 7

sample median

Back 7

• useful when extreme values tend to distort the sample mean...unaffected by extreme values
• represents the value in the middle of a sorted set of values...half of the observations are greater than the median, and half are lower
  

Front 8

if the number of observations is even, the median represents...

Back 8

the average of the two middle observations

Front 9

sample mode

Back 9

• the most commonly observed value in the set of sample values
• reflects the value that occurs with the greatest frequency
• as with the sample median, the mode is unaffected by extreme values
• the only measure of central tendency or location that can be used with qualitative data