Finding the Fourth Proportional to 103,156.86, 142,016.40 and 89,721

Step by Step Solution

1. Step 1: Write the proportion equation
   103,156.86 : 142,016.40 = 89,721 : x
2. Step 2: Convert to fraction form
   103,156.86/142,016.40 = 89,721/x
3. Step 3: Cross multiply
   103,156.86x = 142,016.40 × 89,721
4. Step 4: Simplify right side
   103,156.86x = 12,741,853,424.40
5. Step 5: Solve for x
   x = 12,741,853,424.40/103,156.86
6. Step 6: Final answer
   x = 123,519.21