Finding the Fourth Proportional to 99,786.18, 137,678.63 and 56,766.06

Step by Step Solution

1. Step 1: Write the proportion equation
   99,786.18 : 137,678.63 = 56,766.06 : x
2. Step 2: Convert to fraction form
   99,786.18/137,678.63 = 56,766.06/x
3. Step 3: Cross multiply
   99,786.18x = 137,678.63 × 56,766.06
4. Step 4: Simplify right side
   99,786.18x = 7,815,473,087.47
5. Step 5: Solve for x
   x = 7,815,473,087.47/99,786.18
6. Step 6: Final answer
   x = 78,322.20