Finding the Third Proportional to 1,387.50 and 2,212.50

Step by Step Solution

1. Step 1: Write the proportion equation
   1,387.50 : 2,212.50 = 2,212.50 : x
2. Step 2: Convert to fraction form
   1,387.50/2,212.50 = 2,212.50/x
3. Step 3: Cross multiply
   1,387.50x = 2,212.50 × 2,212.50
4. Step 4: Simplify right side
   1,387.50x = 4,895,156.25
5. Step 5: Solve for x
   x = 4,895,156.25/1,387.50
6. Step 6: Final answer
   x = 3,528.04