Final answer:
To find the current cost of the four-star dinner, multiply the original cost by 250% and add it to the original cost, which results in $350 today.
Step-by-step explanation:
To calculate the cost of a four-star dinner today, which was $100 two decades ago, based on a reported 250% increase, we use the following mathematical expression:
Cost of Dinner Today = Original Cost + (Original Cost × Percentage Increase)
In this case:
Cost of Dinner Today = $100 + ($100 × 2.50)
Cost of Dinner Today = $100 + $250
Cost of Dinner Today = $350
So, a four-star dinner that cost $100 two decades ago would cost $350 today if the price has increased to 250% of the original cost.