Maths Skills

Question 1

3 Reasons why SD is better than a range

Answer 1

SD shows the spread of data around the mean, whereas the range is only difference between highest and lowest

SD reduces the effects of anomalies, but the range includes them

SDs can be used to indicate whether results are significant

Question 2

When to use correlation coefficient

Answer 2

Investigating an association between two co variables

Question 3

When to use students t test

Answer 3

Investigating a difference between two means

Question 4

When to used chi squared

Answer 4

Using frequencies

Investigating a difference

Question 5

When calculating a log for time/s - what should the units be

Answer 5

log (time/s)

Question 6

Why would you use a log scale

Answer 6

If you have a huge range of data, you need to convert to log so you can accurately read data points

Question 7

How to convert log value back to original value (e.g. log 7.55)

Answer 7

You do 10 to the power of that log

e.g 10^7.55