Question

blood is classified by blood type (either a, b, ab or o) and by rh - level as either rh+ or rh-. a phlebotomist classified the blood type and rh - level of the blood of 500 individuals. the data obtained are shown in the contingency table below.

	blood type
rh-	30	4	12	30	76
rh+	176	22	28	198	424
total	206	26	40	228	500

which of the following is the conditional distribution of blood type for rh - level = rh-?

a = 30/76; b = 12/76; ab = 4/76; o = 30/76
a = 30/500; b = 12/500; ab = 4/500; o = 30/500
a = 176/424; b = 28/424; ab = 22/424; o = 198/424
a = 30/206; b = 12/40; ab = 4/26; o = 30/228

Explanation:

Step1: Find total for Rh-.

Total Rh- is 76.

Step2: Calculate conditional probabilities.

For each blood - type, divide count by 76.

Answer:

A. A = 30/76; B = 12/76; AB = 4/76; O = 30/76