Finding the Third Proportional to 61,399.50 and 91,720.50

Step by Step Solution

1. Step 1: Write the proportion equation
   61,399.50 : 91,720.50 = 91,720.50 : x
2. Step 2: Convert to fraction form
   61,399.50/91,720.50 = 91,720.50/x
3. Step 3: Cross multiply
   61,399.50x = 91,720.50 × 91,720.50
4. Step 4: Simplify right side
   61,399.50x = 8,412,650,120.25
5. Step 5: Solve for x
   x = 8,412,650,120.25/61,399.50
6. Step 6: Final answer
   x = 137,014.96