Finding the Fourth Proportional to 42,840.35, 64,302.03 and 20,669.31

Step by Step Solution

1. Step 1: Write the proportion equation
   42,840.35 : 64,302.03 = 20,669.31 : x
2. Step 2: Convert to fraction form
   42,840.35/64,302.03 = 20,669.31/x
3. Step 3: Cross multiply
   42,840.35x = 64,302.03 × 20,669.31
4. Step 4: Simplify right side
   42,840.35x = 1,329,078,591.70
5. Step 5: Solve for x
   x = 1,329,078,591.70/42,840.35
6. Step 6: Final answer
   x = 31,023.99