Final answer:
To calculate the average rate of change from 20 to 40 minutes, we need the change in value over that time period. The formula is (Change in value) / (Change in time). Without context or specific numbers for this time interval, a numerical answer cannot be provided.
Step-by-step explanation:
To calculate the average rate of change from 20 to 40 minutes, we need to know the corresponding change in value for whatever quantity we are interested in during that time interval. The average rate of change is calculated using the formula:
Average rate of change = (Change in value) / (Change in time)
Without knowing the exact context or the specific values corresponding to time at 20 minutes and 40 minutes, we cannot calculate a numerical answer. However, if for example you had a graph showing distance versus time for a train and you wanted to find its average speed between 20 and 40 minutes, you would simply find the train's position on the graph at 20 minutes and at 40 minutes, subtract the former from the latter to find the change in distance, and then divide by the time interval, which is 20 minutes (40 - 20).
If the train traveled 40 miles in one direction and 40 miles back for a total distance of 80 miles in a one hour round trip, we use the following calculation to find the average speed:
Average speed = Total distance / Total time
This would result in an average speed of 80 miles/hour if the round trip took exactly one hour.