Produced by Michael G, former colleague... A great simple run through of Chi Squared... Complete with handouts...

1. The Chi-Squared ( Χ 2 ) Test A test of association

2. The Null and Alternative Hypotheses The Null Hypothesis states that there will be no significant relationship between the data sets The Alternative Hypothesis states that there will be a significant relationship between the data sets So if we were to study the relationship between country size and population what would be the null and the alternative hypotheses

4. The number of buses observed per minute in relation to the distance from the city centre. 2 3 3 2 Σ (O-E) 2 5 1 10 0 (O-E) 2 /E (O-E) Expected frequency (E) No. of buses per min (O) Distance (km)

5. The relationship between the size of pebbles in a river in relation to the distance from its source. 20 3 20 2 Total (O-E) 2 60 1 100 0 (O-E) 2 /E (O-E) Expected frequency (E) Average Diameter of pebbles (mm) (O) Distance from source (km)

6. The number of cars observed in relation to the distance from my house. 44 3 51 2 Total (O-E) 2 53 1 52 0 (O-E) 2 /E (O-E) Expected frequency (E) Number of cars seen (O) Distance from house (km)

10. Task Work through the exam paper. Answer every question on the exam sheet. Those that you do not complete now are to be done for homework.

11. Chi-Squared Quiz!

12. Question 1 You need a total number of observations greater than 10 to carry out the chi-squared test. True or False

13. Question 2 What does the numerical value of the frequency data have to be? A: Precise B: Prime C: Square

14. Question 3 What does the expected frequency in any one category have to be greater than? A: 5 B: 3 C: 7 D: 10

15. Question 4 The formula for chi-squared is? A B C

16. Question 5 Expected values will be the same for every category. True or False