Finding the Third Proportional to 316,789 and 689,346.50

Step by Step Solution

1. Step 1: Write the proportion equation
   316,789 : 689,346.50 = 689,346.50 : x
2. Step 2: Convert to fraction form
   316,789/689,346.50 = 689,346.50/x
3. Step 3: Cross multiply
   316,789x = 689,346.50 × 689,346.50
4. Step 4: Simplify right side
   316,789x = 475,198,597,062.25
5. Step 5: Solve for x
   x = 475,198,597,062.25/316,789
6. Step 6: Final answer
   x = 1,500,047.66