Finding the Fourth Proportional to 9,015.15, 12,438.76 and 5,478.15

Step by Step Solution

1. Step 1: Write the proportion equation
   9,015.15 : 12,438.76 = 5,478.15 : x
2. Step 2: Convert to fraction form
   9,015.15/12,438.76 = 5,478.15/x
3. Step 3: Cross multiply
   9,015.15x = 12,438.76 × 5,478.15
4. Step 4: Simplify right side
   9,015.15x = 68,141,393.09
5. Step 5: Solve for x
   x = 68,141,393.09/9,015.15
6. Step 6: Final answer
   x = 7,558.54