Finding the Fourth Proportional to 13,693.78, 18,897.42 and 7,406.20

Step by Step Solution

1. Step 1: Write the proportion equation
   13,693.78 : 18,897.42 = 7,406.20 : x
2. Step 2: Convert to fraction form
   13,693.78/18,897.42 = 7,406.20/x
3. Step 3: Cross multiply
   13,693.78x = 18,897.42 × 7,406.20
4. Step 4: Simplify right side
   13,693.78x = 139,958,072.00
5. Step 5: Solve for x
   x = 139,958,072.00/13,693.78
6. Step 6: Final answer
   x = 10,220.56