Finding the Fourth Proportional to 9,421.30, 12,999.72 and 5,440.96

Step by Step Solution

1. Step 1: Write the proportion equation
   9,421.30 : 12,999.72 = 5,440.96 : x
2. Step 2: Convert to fraction form
   9,421.30/12,999.72 = 5,440.96/x
3. Step 3: Cross multiply
   9,421.30x = 12,999.72 × 5,440.96
4. Step 4: Simplify right side
   9,421.30x = 70,730,956.53
5. Step 5: Solve for x
   x = 70,730,956.53/9,421.30
6. Step 6: Final answer
   x = 7,507.56