Measures of central tendency

Question 1

How is mean calculated/strengths and weaknesses

Answer 1

Add up all values then divide by total number of values

Strengths:
Uses all data

Weaknesses:
Unrepresentative if there are extreme values
Can only be used for ordinal and interval data

Question 2

How is median calculated/strengths and weaknesses

Answer 2

Arrange values from lowest to highest and find the middle value
In an even number of values, median is halfway between 2 middle scores

Strengths:
Not affected by extreme values

Weaknesses:
Does not use all values

Question 3

How to calculate mode/strengths and weaknesses

Answer 3

Most frequent value

Strengths:
Useful for categorical data
Not affected by extreme outliers

Weaknesses:
Not useful when there are several modes

Question 4

How to calculate range/strengths and weaknesses

Answer 4

Difference between highest and lowest value

Strengths:
Quick and easy

Weaknesses:
Affected by extreme values
Does not take into account all values

Question 5

What does standard deviation show/strengths and weaknesses

Answer 5

Shows how far data is from the mean/whether data is consistent or not
Low SD = Tightly clustered data - data is more consistent
High SD = Spread data - less consistent

Strengths - Uses all values

Weaknesses - Harder to calculate compared to range
Affected by extreme outliers