Finding the Fourth Proportional to 7,165.43, 9,888.15 and 3,978.56

Step by Step Solution

1. Step 1: Write the proportion equation
   7,165.43 : 9,888.15 = 3,978.56 : x
2. Step 2: Convert to fraction form
   7,165.43/9,888.15 = 3,978.56/x
3. Step 3: Cross multiply
   7,165.43x = 9,888.15 × 3,978.56
4. Step 4: Simplify right side
   7,165.43x = 39,340,567.16
5. Step 5: Solve for x
   x = 39,340,567.16/7,165.43
6. Step 6: Final answer
   x = 5,490.33