Question

The numbers 5, 10, 15, and 20 are written on slips of paper, which are then placed in a hat. Two slips are randomly selected with replacement. Find the mean of the samples where the first is smaller than the second.

Answer 1

Solution:

Given numbers = 5, 10, 15, and 20

Samples of size 2 where the first is smaller than the second= {(5,10),(5,15),(5,20),(10,15),(10,20),(15,20)}

Mean of samples$=\dfrac{\frac{5+10}2+\frac{5+15}2+\frac{5+20}2+\frac{15+10}2+\frac{20+10}2+\frac{15+20}2}{6}$

$=\dfrac{7.5+10+12.5+12.5+15+17.5}6 \\=\dfrac{75}6 \\=12.5$