Finding the Third Proportional to 187,990 and 391,470.75

Step by Step Solution

1. Step 1: Write the proportion equation
   187,990 : 391,470.75 = 391,470.75 : x
2. Step 2: Convert to fraction form
   187,990/391,470.75 = 391,470.75/x
3. Step 3: Cross multiply
   187,990x = 391,470.75 × 391,470.75
4. Step 4: Simplify right side
   187,990x = 153,249,348,105.56
5. Step 5: Solve for x
   x = 153,249,348,105.56/187,990
6. Step 6: Final answer
   x = 815,199.47