Using the sample, which is the best prediction of the number of jellybeans in the bag?

Question

There are 24 red jellybeans in a bag of 140 jellybeans. Let the integers 1-24 represent the red jellybeans in a calculator simulation of the situation that generates random integers from 1-140. A sample of 15 "jellybeans" gives the following: 38, 6, 69, 115, 17, 53, 96, 104, 21, 77, 43, 29, 39, 55, 71. 

 

I don't understand random samples, so please explain. 

Answer 1

What this means is that jelly bean 6, 17, and 21 were considered to be red ones. Based on this sample of 15 you would expect 1/5th of the beans to be red. This is the sample proportion. The real proportion is .171.

 

Using 20% as the estimate the predicted number of red beans would be 28.