descriptive statistics

Question 1

What is the mean?

Answer 1

The average score, calculated by dividing the total by the number of values.

Question 2

Strengths and weaknesses of the mean?

Answer 2

Uses all data → most representative measure
Suitable for further statistical tests
− Affected by extreme values (outliers)
− Not suitable for skewed distributions

Question 3

What is the median?

Answer 3

The middle value when data is arranged in order

Question 4

Strengths and weaknesses of the median?

Answer 4

Not affected by outliers
Suitable for skewed data
− Does not use all values
− Less sensitive than mean

Question 5

What is the mode?

Answer 5

The most frequently occurring value.

Question 6

Strengths and weaknesses of the mode?

Answer 6

Easy to identify
Only measure suitable for nominal data
− May not be representative
− Can be more than one mode or none

Question 7

What is the range?

Answer 7

The difference between the highest and lowest value.

Question 8

Strengths and weaknesses of range?

Answer 8

Quick and easy to calculate
Gives a basic measure of spread
− Affected by extreme values
− Does not show distribution of data

Question 9

What is standard deviation?

Answer 9

A measure of how much scores deviate from the mean, showing spread of data.

Question 10

Strengths and weaknesses of standard deviation?

Answer 10

Uses all data → very accurate measure of spread
Useful for comparing datasets
− More complex to calculate
− Can be affected by extreme values

Question 11

what are the steps of standard deviation?

Answer 11

1. calculate mean
2. take mean away from all individual values
3. square each new value
4. find the sum of all values
5. divide the sum from step 4 by (n-1)/x where x is the number of original values and n is the mean
6. square root for final answer