Finding the Fourth Proportional to 42,638.91, 63,972.48 and 13,057.00

Step by Step Solution

1. Step 1: Write the proportion equation
   42,638.91 : 63,972.48 = 13,057.00 : x
2. Step 2: Convert to fraction form
   42,638.91/63,972.48 = 13,057.00/x
3. Step 3: Cross multiply
   42,638.91x = 63,972.48 × 13,057.00
4. Step 4: Simplify right side
   42,638.91x = 835,288,560.39
5. Step 5: Solve for x
   x = 835,288,560.39/42,638.91
6. Step 6: Final answer
   x = 19,589.82