Finding the Fourth Proportional to 42,818.40, 64,233.75 and 13,238.54

Step by Step Solution

1. Step 1: Write the proportion equation
   42,818.40 : 64,233.75 = 13,238.54 : x
2. Step 2: Convert to fraction form
   42,818.40/64,233.75 = 13,238.54/x
3. Step 3: Cross multiply
   42,818.40x = 64,233.75 × 13,238.54
4. Step 4: Simplify right side
   42,818.40x = 850,361,068.73
5. Step 5: Solve for x
   x = 850,361,068.73/42,818.40
6. Step 6: Final answer
   x = 19,859.71