Finding the Third Proportional to 20,128.50 and 42,585.75

Step by Step Solution

1. Step 1: Write the proportion equation
   20,128.50 : 42,585.75 = 42,585.75 : x
2. Step 2: Convert to fraction form
   20,128.50/42,585.75 = 42,585.75/x
3. Step 3: Cross multiply
   20,128.50x = 42,585.75 × 42,585.75
4. Step 4: Simplify right side
   20,128.50x = 1,813,546,103.06
5. Step 5: Solve for x
   x = 1,813,546,103.06/20,128.50
6. Step 6: Final answer
   x = 90,098.42