This problem involves proportions and also different units of measure.
So, first, let's write the distance the worm can crawl in 1 1/2 hour using inches.
We know that 1 foot = 12 inches. So, we have:
6 feet 8 inches = 6 * 12 inches + 8 inches
= 72 inches + 8 inches
= 80 inches
Also, notice that:
1 1/2 hour = (1 + 1/2) hour = 1.5 hour
Now, we have the proportions:
distance (in inches) time (in hour)
80 1.5
x 1
Now, we cross multiply those values to find:
1 * 80 = 1.5 * x
80 = 1.5 x
80/1.5 = 1.5x/1.5
80/1.5 = x
x = 80/1.5
x ≅ 53.33
So, we found that the worm can crawl approximately 53.33 inches per hour.
If we want to know its rate in feet per hour, we need to divide the result by 12:
1 foot = 12 inches
1/12 foot = 1 inch
53.33 inches = 53.33 (1/12 foot)
= (53.33/12) feet
≅ 4.44 feet
Therefore, the worm's rate is approximately 4.44 feet per hour.