Finding the Third Proportional to 318,480 and 488,779.50

Step by Step Solution

1. Step 1: Write the proportion equation
   318,480 : 488,779.50 = 488,779.50 : x
2. Step 2: Convert to fraction form
   318,480/488,779.50 = 488,779.50/x
3. Step 3: Cross multiply
   318,480x = 488,779.50 × 488,779.50
4. Step 4: Simplify right side
   318,480x = 238,905,399,620.25
5. Step 5: Solve for x
   x = 238,905,399,620.25/318,480
6. Step 6: Final answer
   x = 750,142.55