Finding the Fourth Proportional to 42,865.38, 64,314.93 and 13,285.50

Step by Step Solution

1. Step 1: Write the proportion equation
   42,865.38 : 64,314.93 = 13,285.50 : x
2. Step 2: Convert to fraction form
   42,865.38/64,314.93 = 13,285.50/x
3. Step 3: Cross multiply
   42,865.38x = 64,314.93 × 13,285.50
4. Step 4: Simplify right side
   42,865.38x = 854,456,002.52
5. Step 5: Solve for x
   x = 854,456,002.52/42,865.38
6. Step 6: Final answer
   x = 19,933.48