Finding the Fourth Proportional to 260,081.34, 390,234.69 and 91,721.97

Step by Step Solution

1. Step 1: Write the proportion equation
   260,081.34 : 390,234.69 = 91,721.97 : x
2. Step 2: Convert to fraction form
   260,081.34/390,234.69 = 91,721.97/x
3. Step 3: Cross multiply
   260,081.34x = 390,234.69 × 91,721.97
4. Step 4: Simplify right side
   260,081.34x = 35,793,094,529.14
5. Step 5: Solve for x
   x = 35,793,094,529.14/260,081.34
6. Step 6: Final answer
   x = 137,622.69