Finding the Fourth Proportional to 42,818.43, 64,233.80 and 13,238.57

Step by Step Solution

1. Step 1: Write the proportion equation
   42,818.43 : 64,233.80 = 13,238.57 : x
2. Step 2: Convert to fraction form
   42,818.43/64,233.80 = 13,238.57/x
3. Step 3: Cross multiply
   42,818.43x = 64,233.80 × 13,238.57
4. Step 4: Simplify right side
   42,818.43x = 850,363,270.30
5. Step 5: Solve for x
   x = 850,363,270.30/42,818.43
6. Step 6: Final answer
   x = 19,859.75