A particular sale involves four items randomly selected from a large lot that is known to contain 9% defectives. Let X denote the number of defectives among the four sold. The purchaser of the items will return the defectives for repair, and the repair cost is given by 2 C X X = + + 3 2 1. Find the expected repair cost

The expected repair cost is $3.73.

Step-by-step explanation:

The random variable X is defined as the number of defectives among the 4 items sold.

The probability of a large lot of items containing defectives is, p = 0.09.

An item is defective irrespective of the others.

The random variable X follows a Binomial distribution with parameters n = 9 and p = 0.09.

The repair cost of the item is given by:

Compute the expected cost of repair as follows:

Compute the expected value of X as follows:

The expected value of X is 0.36.

Compute the variance of X as follows:

The variance of X is 0.3276.

The variance can also be computed using the formula:

Then the formula of is:

Compute the value of as follows:

The expected repair cost is:

Thus, the expected repair cost is $3.73.

step-by-step explanation:

dong do iy iys a scram

answer: (1,3) and (-2,0) i think.