Finding the Third Proportional to 55,123.50 and 87,399.75

Step by Step Solution

1. Step 1: Write the proportion equation
   55,123.50 : 87,399.75 = 87,399.75 : x
2. Step 2: Convert to fraction form
   55,123.50/87,399.75 = 87,399.75/x
3. Step 3: Cross multiply
   55,123.50x = 87,399.75 × 87,399.75
4. Step 4: Simplify right side
   55,123.50x = 7,638,716,300.06
5. Step 5: Solve for x
   x = 7,638,716,300.06/55,123.50
6. Step 6: Final answer
   x = 138,574.59