Finding the Fourth Proportional to 12,868.72, 19,312.29 and 5,478.37

Step by Step Solution

1. Step 1: Write the proportion equation
   12,868.72 : 19,312.29 = 5,478.37 : x
2. Step 2: Convert to fraction form
   12,868.72/19,312.29 = 5,478.37/x
3. Step 3: Cross multiply
   12,868.72x = 19,312.29 × 5,478.37
4. Step 4: Simplify right side
   12,868.72x = 105,799,870.17
5. Step 5: Solve for x
   x = 105,799,870.17/12,868.72
6. Step 6: Final answer
   x = 8,221.48