Finding the Fourth Proportional to 21,521.53, 29,702.50 and 12,090.09

Step by Step Solution

1. Step 1: Write the proportion equation
   21,521.53 : 29,702.50 = 12,090.09 : x
2. Step 2: Convert to fraction form
   21,521.53/29,702.50 = 12,090.09/x
3. Step 3: Cross multiply
   21,521.53x = 29,702.50 × 12,090.09
4. Step 4: Simplify right side
   21,521.53x = 359,105,979.38
5. Step 5: Solve for x
   x = 359,105,979.38/21,521.53
6. Step 6: Final answer
   x = 16,685.89