Finding the Fourth Proportional to 13,389.30, 18,478.33 and 7,422.74

Step by Step Solution

1. Step 1: Write the proportion equation
   13,389.30 : 18,478.33 = 7,422.74 : x
2. Step 2: Convert to fraction form
   13,389.30/18,478.33 = 7,422.74/x
3. Step 3: Cross multiply
   13,389.30x = 18,478.33 × 7,422.74
4. Step 4: Simplify right side
   13,389.30x = 137,159,797.57
5. Step 5: Solve for x
   x = 137,159,797.57/13,389.30
6. Step 6: Final answer
   x = 10,243.99