For developing countries in Africa and the Americas, let p1 and p2 be the respective proportions of babies with a low birth weight (below 2500 grams). We shall test H0: p1 = p2 against the alternative hypothesis H1: p1 > p2.
(a) Define a critical region that has an α = 0.05 significance level.
(b) If respective random samples of sizes n1 = 900 and n2 = 700 yielded y1 = 135 and y2 = 77 babies with a low birth weight, what is your conclusion?
(c) What would your decision be with a significance level of α = 0.01?
(d) What is the p-value of your test?
Thursday, January 5 th Kim Gilbert Kimgilb@uga.edu TA Office Hours, Boyd Room 204 • Monday 11:15 am – 5:30 pm • Friday 11:15 am – 3:30 pm Case Study: Helper vs. Hinderer • If infants have no preference, then the outcome can be mimicked by flipping a fair coin • Each coin represents one child; need to toss coin 16 times o Would expect 8 but doesn't need to be exactly 8 o Tail: helper; head: hinderer o How close to 8 does it