Chapter 10.8, Problem 28CCR

To determine

The possible number of red jellybeans in the package.

Answer to Problem 28CCR

The expected number of red jellybeans in the package is 75.

Explanation of Solution

Given: A random sample of jellybeans were taken from a package without looking and it was found that 30% of them were red. The package contains 250 jellybeans.

The total number of jellybeans in the package is 250. However, there is no information on whether the distribution of different colors of jellybeans is uniform or not and the number of jellybeans taken out in the random sample isn’t specified either. As a result, it isn’t possible to determine the exact number red jellybeans in package. However, if the probability of getting a red jellybean from the package itself is considered to be 30% then the number of red jellybeans that can be expected is

= 30% of 250

= $\frac{30}{100}\times 250$

= 75

Thus, there might be 75 red jellybeans in the package.