Finding the Third Proportional to 8,427.80 and 12,139.88

Step by Step Solution

1. Step 1: Write the proportion equation
   8,427.80 : 12,139.88 = 12,139.88 : x
2. Step 2: Convert to fraction form
   8,427.80/12,139.88 = 12,139.88/x
3. Step 3: Cross multiply
   8,427.80x = 12,139.88 × 12,139.88
4. Step 4: Simplify right side
   8,427.80x = 147,376,565.02
5. Step 5: Solve for x
   x = 147,376,565.02/8,427.80
6. Step 6: Final answer
   x = 17,486.96