The distribution of the number of chocolate chips (x) in a cookie is shown in the following table. Find the mean and the variance of the number of chocolate chips in a cookie.

Question

Quizplus · Accepted Answer

To find the mean, we multiply each value of x by its corresponding probability, then add up all the products.

mean = (0)(0.1) + (1)(0.3) + (2)(0.2) + (3)(0.2) + (4)(0.1) + (5)(0.1) = 1.9

To find the variance, we need to first find the squared deviation from the mean for each value of x, multiply each squared deviation by its corresponding probability, then add up all the products.

variance = (0 - 1.9)^2(0.1) + (1 - 1.9)^2(0.3) + (2 - 1.9)^2(0.2) + (3 - 1.9)^2(0.2) + (4 - 1.9)^2(0.1) + (5 - 1.9)^2(0.1) = 1.19

Therefore, the best choice is B, with a mean of 1.9 and a variance of 1.19.

The Distribution of the Number of Chocolate Chips (X) in a Cookie