Finding the Fourth Proportional to 12,151.92, 18,242.94 and 7,978.86

Step by Step Solution

1. Step 1: Write the proportion equation
   12,151.92 : 18,242.94 = 7,978.86 : x
2. Step 2: Convert to fraction form
   12,151.92/18,242.94 = 7,978.86/x
3. Step 3: Cross multiply
   12,151.92x = 18,242.94 × 7,978.86
4. Step 4: Simplify right side
   12,151.92x = 145,557,864.25
5. Step 5: Solve for x
   x = 145,557,864.25/12,151.92
6. Step 6: Final answer
   x = 11,978.18