Finding the Third Proportional to 61,980.75 and 90,978.75

Step by Step Solution

1. Step 1: Write the proportion equation
   61,980.75 : 90,978.75 = 90,978.75 : x
2. Step 2: Convert to fraction form
   61,980.75/90,978.75 = 90,978.75/x
3. Step 3: Cross multiply
   61,980.75x = 90,978.75 × 90,978.75
4. Step 4: Simplify right side
   61,980.75x = 8,277,132,951.56
5. Step 5: Solve for x
   x = 8,277,132,951.56/61,980.75
6. Step 6: Final answer
   x = 133,543.61