The Chi-Squared Test

Question 1

What is the chi squared test

Answer 1

Used to test the null hypothesis

The null hypothesis is used to examine the results of scientific investigations and is based on the assumption that there will be no statistically significant differences between sets of observations, any difference being due to chance alone

Question 2

What criteria has to be met to do the chi squared test

Answer 2

Sample size must be relatively large. Over 20

The data must fall into discrete categories

Only raw doubts and not percentages

Is is used to compare experimental results with theoretical ones

Question 3

Whats the chi squared formula

Answer 3

The sum of observed numbers - expected numbers squared divided by expected numbers

Sum of (O-E)* / E

Question 4

What is the smallest value accepted by statisticians for results being due to chance

Answer 4

0.05

Question 5

What happens if the probability is greater or less then 5%

Answer 5

Greater - the deviation is said to be not significant and the null hypothesis will be accepted

Less- he deviation is said to be significant and null hypothesis will be rejected