To find out how many gallons of gas Mrs. Ebert would need for the total trip of 840 miles, we can set up a proportion.
The proportion would be:
552 miles / 23 gallons = 840 miles / x gallons.
To solve this proportion, we can cross multiply:
552 * x = 23 * 840.
We can solve for x by dividing both sides of the equation by 552:
x = (23 * 840) / 552.
x = 34860 / 552.
x ≈ 63.26.
Therefore, Mrs. Ebert would need approximately 63.26 gallons of gas for the total trip of 840 miles.