Finding the Fourth Proportional to 13,690.29, 18,892.59 and 7,721.94

Step by Step Solution

1. Step 1: Write the proportion equation
   13,690.29 : 18,892.59 = 7,721.94 : x
2. Step 2: Convert to fraction form
   13,690.29/18,892.59 = 7,721.94/x
3. Step 3: Cross multiply
   13,690.29x = 18,892.59 × 7,721.94
4. Step 4: Simplify right side
   13,690.29x = 145,887,446.42
5. Step 5: Solve for x
   x = 145,887,446.42/13,690.29
6. Step 6: Final answer
   x = 10,656.27