Finding the Third Proportional to 59,989 and 87,679.50

Step by Step Solution

1. Step 1: Write the proportion equation
   59,989 : 87,679.50 = 87,679.50 : x
2. Step 2: Convert to fraction form
   59,989/87,679.50 = 87,679.50/x
3. Step 3: Cross multiply
   59,989x = 87,679.50 × 87,679.50
4. Step 4: Simplify right side
   59,989x = 7,687,694,720.25
5. Step 5: Solve for x
   x = 7,687,694,720.25/59,989
6. Step 6: Final answer
   x = 128,151.74