Finding the Third Proportional to 78,178.50 and 90,490.50

Step by Step Solution

1. Step 1: Write the proportion equation
   78,178.50 : 90,490.50 = 90,490.50 : x
2. Step 2: Convert to fraction form
   78,178.50/90,490.50 = 90,490.50/x
3. Step 3: Cross multiply
   78,178.50x = 90,490.50 × 90,490.50
4. Step 4: Simplify right side
   78,178.50x = 8,188,530,590.25
5. Step 5: Solve for x
   x = 8,188,530,590.25/78,178.50
6. Step 6: Final answer
   x = 104,741.46