Finding the Fourth Proportional to 38,978.64, 58,454.16 and 12,678.48

Step by Step Solution

1. Step 1: Write the proportion equation
   38,978.64 : 58,454.16 = 12,678.48 : x
2. Step 2: Convert to fraction form
   38,978.64/58,454.16 = 12,678.48/x
3. Step 3: Cross multiply
   38,978.64x = 58,454.16 × 12,678.48
4. Step 4: Simplify right side
   38,978.64x = 741,109,898.48
5. Step 5: Solve for x
   x = 741,109,898.48/38,978.64
6. Step 6: Final answer
   x = 19,013.23