Finding the Fourth Proportional to 40,980.72, 61,470.72 and 13,278.72

Step by Step Solution

1. Step 1: Write the proportion equation
   40,980.72 : 61,470.72 = 13,278.72 : x
2. Step 2: Convert to fraction form
   40,980.72/61,470.72 = 13,278.72/x
3. Step 3: Cross multiply
   40,980.72x = 61,470.72 × 13,278.72
4. Step 4: Simplify right side
   40,980.72x = 816,252,479.08
5. Step 5: Solve for x
   x = 816,252,479.08/40,980.72
6. Step 6: Final answer
   x = 19,917.96