19. A The National Red Cross says that about 11% of the US population has type B blood. A b drive is being held at your school.What is the probability that at least 2 out of the first 10 b donors has type B blood? (a) 0.088 (b) 0.214 (c) 0.697 (d) 0.303 (e) None of the above.

## Step 1: Calculate the probability of exactly 0 donors having type B blood.<br />### The probability of a single donor *not* having type B blood is $1 - 0.11 = 0.89$. The probability of 0 out of 10 donors having type B blood is given by the binomial probability formula: $P(X=0) = \binom{10}{0} (0.11)^0 (0.89)^{10} \approx 0.3118$.<br /><br />## Step 2: Calculate the probability of exactly 1 donor having type B blood.<br />### The probability of exactly 1 out of 10 donors having type B blood is given by the binomial probability formula: $P(X=1) = \binom{10}{1} (0.11)^1 (0.89)^{9} \approx 0.3854$.<br /><br />## Step 3: Calculate the probability of at least 2 donors having type B blood.<br />### The probability of at least 2 donors having type B blood is the complement of the probabilities of 0 or 1 donor having type B blood: $P(X \ge 2) = 1 - P(X=0) - P(X=1) = 1 - 0.3118 - 0.3854 \approx 0.3028$. This is closest to option (d).