Finding the Fourth Proportional to 261,339.57, 391,852.52 and 90,505

Step by Step Solution

1. Step 1: Write the proportion equation
   261,339.57 : 391,852.52 = 90,505 : x
2. Step 2: Convert to fraction form
   261,339.57/391,852.52 = 90,505/x
3. Step 3: Cross multiply
   261,339.57x = 391,852.52 × 90,505
4. Step 4: Simplify right side
   261,339.57x = 35,464,612,322.60
5. Step 5: Solve for x
   x = 35,464,612,322.60/261,339.57
6. Step 6: Final answer
   x = 135,703.19