Maths skills

Question 1

What is a strength of the mean?

Answer 1

• Most accurate and sensitive measure
• Takes all scores into account
• Needed if want to work out the standard deviation.

Question 2

What is a weakness of the mean?

Answer 2

Can be affected by outliers/ extreme scores.

Question 3

What is a strength of the mode?

Answer 3

Unaffected by outliers/ extreme scores.

Question 4

What is a weakness of the mode?

Answer 4

Not as accurate as only takes into account the scores most commonly used.

Question 5

What is a strength of the median?

Answer 5

Unaffected by outliers/ extreme scores

Question 6

What is a weakness of the median?

Answer 6

Not as accurate as only takes into account the middle score

Question 7

What is an advantage and disadvantage of range?

Answer 7

Advantages: Easy to calculate.

Disadvantages: May be affected by extreme scores. Does not indicate how widely or tightly spread the data are. Does not use all pieces of data.

Question 8

What is standard deviation?

Answer 8

1 - Calculate the mean of the data set.
2 - Take the mean away from each score in the data set.
3 - Square each difference.
4 - Add together each of the squared differences
5 - Divide this by n-1 (the number of scores in your data set - 1)
6 - Find the square root of this value/

Question 9

Advantages of standard deviation…

Answer 9

• Precise measure of dispersion as all exact values are taken into account
• Not difficult to calculate with a calculator
• Highlights if the mean is suitable
• Less affected by extreme scores compared to the range
• Used for further analysis - skew of distribution

Question 10

Disadvantages of standard deviation?

Answer 10

• Can only be used for normally distributed data
• Only for ordinal or above (interval/ratio)
• May hide some characteristics of data set (extreme values)
• Harder to calculate than the range

Question 11

What is a normal distribution graph?

Answer 11

A symmetrical spread of frequency data that forms a bell-shaped pattern.
- The mean, mode and median are at the highest peak.
- The tail end never touches the x axis.

Question 12

How can you check if a distribution is normal?

Answer 12

1 - See if most scores are centered around the mean.
2 - Calculate the measures of central tendency (calculate the mean, mode and median to see if they’re similar).
3 - Plot the frequency of the distribution.