Finding the Fourth Proportional to 12,999.48, 19,511.34 and 7,148.04

Step by Step Solution

1. Step 1: Write the proportion equation
   12,999.48 : 19,511.34 = 7,148.04 : x
2. Step 2: Convert to fraction form
   12,999.48/19,511.34 = 7,148.04/x
3. Step 3: Cross multiply
   12,999.48x = 19,511.34 × 7,148.04
4. Step 4: Simplify right side
   12,999.48x = 139,467,838.77
5. Step 5: Solve for x
   x = 139,467,838.77/12,999.48
6. Step 6: Final answer
   x = 10,728.72