Question

The probability that an individual is left-handed is 0.19. In a class of 90 students, what is the mean and standard deviation of the number of left-handed students? Round to the nearest hundredth when necessary.

Answer 1

Mean = 17.1

SD = 3.72

Explanation:

FROM the question;

n = 0.19 and the probability of success is 0.19

Mean = np = 0.19 * 90 = 17.1

The standard deviation is as follows;

√np(1-p)

SD = √(17.1)(0.81)

SD = √13.851

SD = 3.72