Finding the Fourth Proportional to 21,061.60, 31,603.38 and 8,590.84

Step by Step Solution

1. Step 1: Write the proportion equation
   21,061.60 : 31,603.38 = 8,590.84 : x
2. Step 2: Convert to fraction form
   21,061.60/31,603.38 = 8,590.84/x
3. Step 3: Cross multiply
   21,061.60x = 31,603.38 × 8,590.84
4. Step 4: Simplify right side
   21,061.60x = 271,499,581.04
5. Step 5: Solve for x
   x = 271,499,581.04/21,061.60
6. Step 6: Final answer
   x = 12,890.74