Answer to Question #295710 in Psychology for Eti

Question

Out of 2000 people, 500 got vaccinated for smallpox and the rest did not. Out of the people who got vaccinated 31 succumbed to the illness while the rest did not. Out of the 1500 who did not get vaccinated, 185 got smallpox while the others did not. Test the effectiveness of vaccination in preventing smallpox. Test your result with the help of chi square at 5 percent level of significance.

Answer 1

Total sample population $=$ 2000

Vaccinated population$=$ 500

Of the vaccinated, 31 died while 469 survived.

Of the 1500, 185 got the illness. So 1315 survived.

Test for significance

Vaccinated

Well Died x²

469 31 1.60

Unvaccinated

Well ill x²

1315 185 2.99

Total x² $=$ 4.59

At 5% level it higher than the 4.59, hence the vaccine is effective.$\%$ $\%$