Finding the Fourth Proportional to 13,389.98, 18,476.20 and 7,421.63

Step by Step Solution

1. Step 1: Write the proportion equation
   13,389.98 : 18,476.20 = 7,421.63 : x
2. Step 2: Convert to fraction form
   13,389.98/18,476.20 = 7,421.63/x
3. Step 3: Cross multiply
   13,389.98x = 18,476.20 × 7,421.63
4. Step 4: Simplify right side
   13,389.98x = 137,123,437.10
5. Step 5: Solve for x
   x = 137,123,437.10/13,389.98
6. Step 6: Final answer
   x = 10,240.75