Finding the Fourth Proportional to 9,867.14, 13,616.42 and 5,390.90

Step by Step Solution

1. Step 1: Write the proportion equation
   9,867.14 : 13,616.42 = 5,390.90 : x
2. Step 2: Convert to fraction form
   9,867.14/13,616.42 = 5,390.90/x
3. Step 3: Cross multiply
   9,867.14x = 13,616.42 × 5,390.90
4. Step 4: Simplify right side
   9,867.14x = 73,404,663.54
5. Step 5: Solve for x
   x = 73,404,663.54/9,867.14
6. Step 6: Final answer
   x = 7,439.31