Question

In a sample of 400 californians, 280 of them own a car. In a sample of 300 Texans, 62% own a car. Is there a difference in the proportions?

Answer 1

Claim: Difference in proportion

n1 = sample size = 400

x1= number of success = 280

n2 =sample size = 300

x2 = 0.62*300= 186

Test Statistics :

Z = 2.22

Using Z table check 2.2 row and 0.02 column we get 0.9868 . But we have two tailed test so we use 2*(1-0.9868) = 0.0264

P value = 0.0264

P value < 0.05 we reject Ho.

Conclusion : There is enough evidence to conclude that there is difference in proportion