Finding the Fourth Proportional to 9,402.85, 12,978.69 and 5,426.74

Step by Step Solution

1. Step 1: Write the proportion equation
   9,402.85 : 12,978.69 = 5,426.74 : x
2. Step 2: Convert to fraction form
   9,402.85/12,978.69 = 5,426.74/x
3. Step 3: Cross multiply
   9,402.85x = 12,978.69 × 5,426.74
4. Step 4: Simplify right side
   9,402.85x = 70,431,976.17
5. Step 5: Solve for x
   x = 70,431,976.17/9,402.85
6. Step 6: Final answer
   x = 7,490.49