Finding the Fourth Proportional to 42,838.37, 64,260.28 and 13,253.72

Step by Step Solution

1. Step 1: Write the proportion equation
   42,838.37 : 64,260.28 = 13,253.72 : x
2. Step 2: Convert to fraction form
   42,838.37/64,260.28 = 13,253.72/x
3. Step 3: Cross multiply
   42,838.37x = 64,260.28 × 13,253.72
4. Step 4: Simplify right side
   42,838.37x = 851,687,758.24
5. Step 5: Solve for x
   x = 851,687,758.24/42,838.37
6. Step 6: Final answer
   x = 19,881.43