Finding the Fourth Proportional to 13,185.80, 19,761.42 and 5,385.68

Step by Step Solution

1. Step 1: Write the proportion equation
   13,185.80 : 19,761.42 = 5,385.68 : x
2. Step 2: Convert to fraction form
   13,185.80/19,761.42 = 5,385.68/x
3. Step 3: Cross multiply
   13,185.80x = 19,761.42 × 5,385.68
4. Step 4: Simplify right side
   13,185.80x = 106,428,684.47
5. Step 5: Solve for x
   x = 106,428,684.47/13,185.80
6. Step 6: Final answer
   x = 8,071.46