Finding the Third Proportional to 318,111.75 and 418,108.50

Step by Step Solution

1. Step 1: Write the proportion equation
   318,111.75 : 418,108.50 = 418,108.50 : x
2. Step 2: Convert to fraction form
   318,111.75/418,108.50 = 418,108.50/x
3. Step 3: Cross multiply
   318,111.75x = 418,108.50 × 418,108.50
4. Step 4: Simplify right side
   318,111.75x = 174,814,717,772.25
5. Step 5: Solve for x
   x = 174,814,717,772.25/318,111.75
6. Step 6: Final answer
   x = 549,538.70