Question

We wish to compare the prevalence of parasites in Mediterranean fish to the prevalence of parasites in Atlantic fish. In the Mediterranean Sea 500 brill were captured and dissected; 200 were found to contain parasites   In the Atlantic 200 brill were captured and dissected; 40 were found to have parasites. In what follows, let p₁ denotes the infestation rate for the Mediterranean brill and p₂ denote the infestation rate for the Atlantic brill. Find the point estimate for the difference p₁   - p_2.

0.35

160

0.20

0.10

0.60

Answer 1

Solution:

p1 = x / n = 200 / 500

p1 = 0.40

p2 = x / n = 40 /200

p2 = 0.20

Point estimate = p1 - p2 = 0.40 - 0.20

= 0.20