Finding the Fourth Proportional to 21,601.60, 29,819.76 and 15,926.56

Step by Step Solution

1. Step 1: Write the proportion equation
   21,601.60 : 29,819.76 = 15,926.56 : x
2. Step 2: Convert to fraction form
   21,601.60/29,819.76 = 15,926.56/x
3. Step 3: Cross multiply
   21,601.60x = 29,819.76 × 15,926.56
4. Step 4: Simplify right side
   21,601.60x = 474,926,196.83
5. Step 5: Solve for x
   x = 474,926,196.83/21,601.60
6. Step 6: Final answer
   x = 21,985.70