Finding the Fourth Proportional to 42,839.35, 64,300.53 and 20,668.31

Step by Step Solution

1. Step 1: Write the proportion equation
   42,839.35 : 64,300.53 = 20,668.31 : x
2. Step 2: Convert to fraction form
   42,839.35/64,300.53 = 20,668.31/x
3. Step 3: Cross multiply
   42,839.35x = 64,300.53 × 20,668.31
4. Step 4: Simplify right side
   42,839.35x = 1,328,983,646.03
5. Step 5: Solve for x
   x = 1,328,983,646.03/42,839.35
6. Step 6: Final answer
   x = 31,022.50