Finding the Third Proportional to 421,920 and 563,611.50

Step by Step Solution

1. Step 1: Write the proportion equation
   421,920 : 563,611.50 = 563,611.50 : x
2. Step 2: Convert to fraction form
   421,920/563,611.50 = 563,611.50/x
3. Step 3: Cross multiply
   421,920x = 563,611.50 × 563,611.50
4. Step 4: Simplify right side
   421,920x = 317,657,922,932.25
5. Step 5: Solve for x
   x = 317,657,922,932.25/421,920
6. Step 6: Final answer
   x = 752,886.62