Finding the Fourth Proportional to 11,980.64, 17,978.15 and 4,960.78

Step by Step Solution

1. Step 1: Write the proportion equation
   11,980.64 : 17,978.15 = 4,960.78 : x
2. Step 2: Convert to fraction form
   11,980.64/17,978.15 = 4,960.78/x
3. Step 3: Cross multiply
   11,980.64x = 17,978.15 × 4,960.78
4. Step 4: Simplify right side
   11,980.64x = 89,185,614.41
5. Step 5: Solve for x
   x = 89,185,614.41/11,980.64
6. Step 6: Final answer
   x = 7,444.14