Answer:
2 proportions z test
The two populations are named as residents from the first county and residents from the second county.
Step-by-step explanation:
This is testing hypothesis about the difference between two proportions.
When the proportions are tested if they are the test statistic
z= ( p^1-p^2)- (p1-p2) / √p₁q₁/n₁ + p₂q₂/ n₂
where p^1 is the proportion of success in the first sample and p^2 of size n₁ is the proportion of success in the second sample of size n₂ with unknown proportions of successes p1 and p2 respectively.
When the sample sizes are sufficiently large
z= ( p^1-p^2)- (p1-p2) / √p₁q₁/n₁ + p₂q₂/ n₂ is approximately standard normal.
The two populations are named as residents from the first county and residents from the second county.