Final answer:
The percent of change from 20 to 38 is found by calculating the change in quantity (which is 18), dividing that by the original quantity (20), and then multiplying by 100 to get a percentage, which yields a 90% increase.
Step-by-step explanation:
To calculate the percent of change from 20 to 38, you can use the following formula:
Percentage change = [(change in quantity) / (original quantity)] × 100
First, find the change in quantity:
38 - 20 = 18
Next, divide this change by the original quantity:
18 / 20 = 0.9
Finally, to find the percentage change, multiply by 100:
0.9 × 100 = 90%
Thus, the percent of change from 20 to 38 is 90%.