Finding the Third Proportional to 399,085.50 and 598,609.50

Step by Step Solution

1. Step 1: Write the proportion equation
   399,085.50 : 598,609.50 = 598,609.50 : x
2. Step 2: Convert to fraction form
   399,085.50/598,609.50 = 598,609.50/x
3. Step 3: Cross multiply
   399,085.50x = 598,609.50 × 598,609.50
4. Step 4: Simplify right side
   399,085.50x = 358,333,333,490.25
5. Step 5: Solve for x
   x = 358,333,333,490.25/399,085.50
6. Step 6: Final answer
   x = 897,886.13