Finding the Fourth Proportional to 13,685.80, 18,886.42 and 7,398.18

Step by Step Solution

1. Step 1: Write the proportion equation
   13,685.80 : 18,886.42 = 7,398.18 : x
2. Step 2: Convert to fraction form
   13,685.80/18,886.42 = 7,398.18/x
3. Step 3: Cross multiply
   13,685.80x = 18,886.42 × 7,398.18
4. Step 4: Simplify right side
   13,685.80x = 139,725,134.72
5. Step 5: Solve for x
   x = 139,725,134.72/13,685.80
6. Step 6: Final answer
   x = 10,209.50