What is the average visibility if the observation states it varies between 1 5/8 and 2 1/4 miles?

To determine the average visibility when it varies between 1 5/8 miles and 2 1/4 miles, it's important to convert these fractions into a form that makes calculation straightforward.

First, convert 1 5/8 miles into an improper fraction:

1 5/8 = (1 * 8 + 5) / 8 = 13/8 miles.

Next, convert 2 1/4 miles:

2 1/4 = (2 * 4 + 1) / 4 = 9/4 miles.

Now, to calculate the average visibility, you can find the midpoint of these two values. Add the two improper fractions:

13/8 + 9/4. To add these together, you need a common denominator, which in this case is 8. Convert 9/4 into eighths:

9/4 = 18/8.

Now, add:

13/8 + 18/8 = 31/8.

To find the average, divide this sum by 2:

(31/8) / 2 = 31/16 miles.

Now, convert 31/16 back to a mixed number:

31/16 equals 1