Finding the Third Proportional to 5,287.50 and 10,428.75

Step by Step Solution

1. Step 1: Write the proportion equation
   5,287.50 : 10,428.75 = 10,428.75 : x
2. Step 2: Convert to fraction form
   5,287.50/10,428.75 = 10,428.75/x
3. Step 3: Cross multiply
   5,287.50x = 10,428.75 × 10,428.75
4. Step 4: Simplify right side
   5,287.50x = 108,758,826.56
5. Step 5: Solve for x
   x = 108,758,826.56/5,287.50
6. Step 6: Final answer
   x = 20,569.05