Question

425 school children were surveyed about what they want to be when they grow up, out of a choice of five professions. The results were Teacher 80, Doctor 105, Lawyer 70, Police officer 70, Firefighter 100. a. Obviously these particular children preferred some occupations over others. Test whether their preference reflects a real difference in the population or not. b. Which of the categories contributed the most to the chi-squared test statistic?

Answer 1

Given:

425 school children

Teacher : 80
Doctor : 105
Lawyer : 70
Police Officer : 70
Firefighter : 100
Total = 425

After applying Pearson's chi-squared test, it is concluded that this data reflects a real difference in the population. 

$x^{2} = summation ((O_i - E_i)^2/E_i)$