Finding the Fourth Proportional to 42,705.98, 64,067.20 and 13,118.56

Step by Step Solution

1. Step 1: Write the proportion equation
   42,705.98 : 64,067.20 = 13,118.56 : x
2. Step 2: Convert to fraction form
   42,705.98/64,067.20 = 13,118.56/x
3. Step 3: Cross multiply
   42,705.98x = 64,067.20 × 13,118.56
4. Step 4: Simplify right side
   42,705.98x = 840,469,407.23
5. Step 5: Solve for x
   x = 840,469,407.23/42,705.98
6. Step 6: Final answer
   x = 19,680.37