Finding the Fourth Proportional to 42,731.58, 64,073.88 and 13,141.20

Step by Step Solution

1. Step 1: Write the proportion equation
   42,731.58 : 64,073.88 = 13,141.20 : x
2. Step 2: Convert to fraction form
   42,731.58/64,073.88 = 13,141.20/x
3. Step 3: Cross multiply
   42,731.58x = 64,073.88 × 13,141.20
4. Step 4: Simplify right side
   42,731.58x = 842,007,671.86
5. Step 5: Solve for x
   x = 842,007,671.86/42,731.58
6. Step 6: Final answer
   x = 19,704.58