Finding the Fourth Proportional to 9,407.12, 12,978.48 and 5,429.24

Step by Step Solution

1. Step 1: Write the proportion equation
   9,407.12 : 12,978.48 = 5,429.24 : x
2. Step 2: Convert to fraction form
   9,407.12/12,978.48 = 5,429.24/x
3. Step 3: Cross multiply
   9,407.12x = 12,978.48 × 5,429.24
4. Step 4: Simplify right side
   9,407.12x = 70,463,282.76
5. Step 5: Solve for x
   x = 70,463,282.76/9,407.12
6. Step 6: Final answer
   x = 7,490.42