Finding the Fourth Proportional to 20,891.79, 31,345.89 and 9,196.81

Step by Step Solution

1. Step 1: Write the proportion equation
   20,891.79 : 31,345.89 = 9,196.81 : x
2. Step 2: Convert to fraction form
   20,891.79/31,345.89 = 9,196.81/x
3. Step 3: Cross multiply
   20,891.79x = 31,345.89 × 9,196.81
4. Step 4: Simplify right side
   20,891.79x = 288,282,194.61
5. Step 5: Solve for x
   x = 288,282,194.61/20,891.79
6. Step 6: Final answer
   x = 13,798.83