Finding the Fourth Proportional to 13,389.18, 18,476.76 and 7,420.83

Step by Step Solution

1. Step 1: Write the proportion equation
   13,389.18 : 18,476.76 = 7,420.83 : x
2. Step 2: Convert to fraction form
   13,389.18/18,476.76 = 7,420.83/x
3. Step 3: Cross multiply
   13,389.18x = 18,476.76 × 7,420.83
4. Step 4: Simplify right side
   13,389.18x = 137,112,894.91
5. Step 5: Solve for x
   x = 137,112,894.91/13,389.18
6. Step 6: Final answer
   x = 10,240.57