Finding the Fourth Proportional to 99,890.69, 137,966.17 and 79,540.88

Step by Step Solution

1. Step 1: Write the proportion equation
   99,890.69 : 137,966.17 = 79,540.88 : x
2. Step 2: Convert to fraction form
   99,890.69/137,966.17 = 79,540.88/x
3. Step 3: Cross multiply
   99,890.69x = 137,966.17 × 79,540.88
4. Step 4: Simplify right side
   99,890.69x = 10,973,950,572.03
5. Step 5: Solve for x
   x = 10,973,950,572.03/99,890.69
6. Step 6: Final answer
   x = 109,859.59