Question

Suppose for a population of collage students, the distribution of the number of times they visited a dentist in the past year is as follows. number of visits 0 1 2 probability 0.5 0.4 0.1 Calculate the population variance

Answer 1

Solution:

Given: For a population of collage students, the distribution of the number of times they visited a dentist in the past year is as follows.

x: Number of visits	P(x) : Probability
0	0.5
1	0.4
2	0.1

We have to calculate the population variance:

Formula:

Thus we need to make following table:

x: Number of visits	P(x) : Probability	x * P(x)	x2 * P(x)
0	0.5	0	0
1	0.4	0.4	0.4
2	0.1	0.2	0.4

Thus

Thus the population variance of the number of times students visited a dentist in the past year is 0.44.