Finding the Fourth Proportional to 12,169.78, 16,794.42 and 7,978

Step by Step Solution

1. Step 1: Write the proportion equation
   12,169.78 : 16,794.42 = 7,978 : x
2. Step 2: Convert to fraction form
   12,169.78/16,794.42 = 7,978/x
3. Step 3: Cross multiply
   12,169.78x = 16,794.42 × 7,978
4. Step 4: Simplify right side
   12,169.78x = 133,985,882.76
5. Step 5: Solve for x
   x = 133,985,882.76/12,169.78
6. Step 6: Final answer
   x = 11,009.72