Finding the Fourth Proportional to 21,160.71, 31,586.56 and 19,618.88

Step by Step Solution

1. Step 1: Write the proportion equation
   21,160.71 : 31,586.56 = 19,618.88 : x
2. Step 2: Convert to fraction form
   21,160.71/31,586.56 = 19,618.88/x
3. Step 3: Cross multiply
   21,160.71x = 31,586.56 × 19,618.88
4. Step 4: Simplify right side
   21,160.71x = 619,692,723.27
5. Step 5: Solve for x
   x = 619,692,723.27/21,160.71
6. Step 6: Final answer
   x = 29,285.06