Arrange 10.135, 10.513, 10.18, and 10.76 in descending order.

Explained below.

Step-by-step explanation:

The random variable X is defined as the number of stars in a given volume of space.

The probability mass function of X is:

(7)

Compute the probability of exactly two stars in 16 cubic light-years as follows:

(8)

Compute the probability of three or more stars in 16 cubic light-years as follows:

(9)

In 16 cubic light years there is only 1 star.

Then in 1 cubic light years there will be, (1/16) stars.

Then in 4 cubic light years there will be, 4 × (1/16) = (1/4) stars.

(10)

In 16 cubic light years there is only 1 star.

Then in 1 cubic light years there will be, (1/16) stars.

Then in t cubic light years there will be, [t × (1/16)] stars.