If a sample of 8 batteries is selected from a lot of 11, of which 4 are defective, what is the expected number of defective batteries? Round your answer to next whole number.
A) 7
B) 10
C) 12
D) 5
E) 6

Question

Quizplus · Accepted Answer

The expected number of defective batteries in a sample of 8 from a lot of 11 with 4 defective batteries can be calculated using the formula for the expected value in a hypergeometric distribution. The expected value E(X) = (n * k) / N, where n is the sample size (8), k is the number of successes in the population (4 defective batteries), and N is the population size (11). So, E(X) = (8 * 4) / 11 = 32 / 11 ≈ 2.91. When rounded to the next whole number, this gives 3, which is not listed among the options provided, indicating a possible mistake in the interpretation of the options or a typo in the question or options.

If a Sample of 8 Batteries Is Selected from a Lot