Finding the Fourth Proportional to 42,821.82, 64,209.65 and 13,231.71

Step by Step Solution

1. Step 1: Write the proportion equation
   42,821.82 : 64,209.65 = 13,231.71 : x
2. Step 2: Convert to fraction form
   42,821.82/64,209.65 = 13,231.71/x
3. Step 3: Cross multiply
   42,821.82x = 64,209.65 × 13,231.71
4. Step 4: Simplify right side
   42,821.82x = 849,603,401.84
5. Step 5: Solve for x
   x = 849,603,401.84/42,821.82
6. Step 6: Final answer
   x = 19,840.43