15 - Measures of Central Tendency

Question 1

Evaluate the mean

Answer 1

+ most accurate - takes into account all the scores

• can be distorted by a single extreme value
• mean score may not be one of the actual scores in the set

Question 2

Evaluate the median

Answer 2

+ unaffected by extreme scores

- not very sensitive as not all scores used, therefore it can be unrepresentative

Question 3

Evaluate the mode

Answer 3

+ unaffected by extreme scores

- tells us nothing about other scores in the data set

Question 4

How can you measure dispersion?

Answer 4

Range

Standard deviation ( average amount each score differs from the mean )

Question 5

Evaluate the range

Answer 5

+ quick and easy to calculate

- easily distorted by extreme values

Question 6

Evaluate standard deviation

Answer 6

+ takes account of all the scores

• more difficult to calculate
• can only be used for interval data

Question 7

What else?

Answer 7

Be able to convert between percentages, decimals and fractions,

Be able to work with ratios