Finding the Fourth Proportional to 191,780.89, 287,825.41 and 86,609.05

Step by Step Solution

1. Step 1: Write the proportion equation
   191,780.89 : 287,825.41 = 86,609.05 : x
2. Step 2: Convert to fraction form
   191,780.89/287,825.41 = 86,609.05/x
3. Step 3: Cross multiply
   191,780.89x = 287,825.41 × 86,609.05
4. Step 4: Simplify right side
   191,780.89x = 24,928,283,886.83
5. Step 5: Solve for x
   x = 24,928,283,886.83/191,780.89
6. Step 6: Final answer
   x = 129,983.15