Finding the Third Proportional to 216,778.50 and 308,131.50

Step by Step Solution

1. Step 1: Write the proportion equation
   216,778.50 : 308,131.50 = 308,131.50 : x
2. Step 2: Convert to fraction form
   216,778.50/308,131.50 = 308,131.50/x
3. Step 3: Cross multiply
   216,778.50x = 308,131.50 × 308,131.50
4. Step 4: Simplify right side
   216,778.50x = 94,945,021,292.25
5. Step 5: Solve for x
   x = 94,945,021,292.25/216,778.50
6. Step 6: Final answer
   x = 437,981.72