Finding the Third Proportional to 402,290 and 554,158.50

Step by Step Solution

1. Step 1: Write the proportion equation
   402,290 : 554,158.50 = 554,158.50 : x
2. Step 2: Convert to fraction form
   402,290/554,158.50 = 554,158.50/x
3. Step 3: Cross multiply
   402,290x = 554,158.50 × 554,158.50
4. Step 4: Simplify right side
   402,290x = 307,091,643,122.25
5. Step 5: Solve for x
   x = 307,091,643,122.25/402,290
6. Step 6: Final answer
   x = 763,358.88