Answer:
The rates are 1/2 yards per hour
Step-by-step explanation:
Here, we want to calculate the rate of change in the amount of yarn
We start by calculating the difference between what we had initially and what we have now
That will be;
3 3/4 - 1 1/8
= 15/4 - 9/8 = 21/8 yards
So we now divide this by the number of hours
21/8 yards divided by 51/4
= 21/8 * 4/21 = 1/2 yards per hour