Finding the Third Proportional to 315,480 and 688,054.50

Step by Step Solution

1. Step 1: Write the proportion equation
   315,480 : 688,054.50 = 688,054.50 : x
2. Step 2: Convert to fraction form
   315,480/688,054.50 = 688,054.50/x
3. Step 3: Cross multiply
   315,480x = 688,054.50 × 688,054.50
4. Step 4: Simplify right side
   315,480x = 473,418,994,970.25
5. Step 5: Solve for x
   x = 473,418,994,970.25/315,480
6. Step 6: Final answer
   x = 1,500,630.77