Stats Tests

Question 1

What are the five different stats tests

Answer 1

• chi - squared
• spearmans rank
• paired students t - test
• unpaired students t - test
• standard deviation

Question 2

What is the students t test used for

Answer 2

Used to compare the means of two sets of data and determine wether they are significantly different or not

Question 3

The sets of data must follow what in students t test?

Answer 3

• a roughly normal distribution
• be continuous
• the standard deviations should be approximately equal

Question 4

Which is the one stats test thats doesn’t need a null hypothesis

Answer 4

Standard deviation

Question 5

How do you work out the degrees of freedom for t test

Answer 5

(N1 - 1) + (n2 - 1)
- N1 = no. Of individual measurements in sample 1
- n2 = no. Of individual measurements in sample 2

Question 6

How do you work out the degrees of freedom

Answer 6

N - 1
- n = number of individual measurements

Question 7

What does standard deviation measure

Answer 7

• The spread of data around the mean
• its useful when comparing consistency between different data sets

Question 8

What is spearman’s rank used for

Answer 8

To determine whether there is a correlation between variables that don’t show a normal distribution

Question 9

If your worked value is greater that the critical value what do you do with the null hypothesis

Answer 9

Reject it

Question 10

What is chi - squared use for

Answer 10

It determines whether or not there is a significant difference between the observed and the expected results in an experiment

Question 11

In chi - squared, if the difference between results IS statistically significant this suggests what

Answer 11

That there is a presence of a factor that isn’t being accounted for, e.g. linkage between genes