Finding the Fourth Proportional to 42,691.32, 64,068.48 and 20,517.48

Step by Step Solution

1. Step 1: Write the proportion equation
   42,691.32 : 64,068.48 = 20,517.48 : x
2. Step 2: Convert to fraction form
   42,691.32/64,068.48 = 20,517.48/x
3. Step 3: Cross multiply
   42,691.32x = 64,068.48 × 20,517.48
4. Step 4: Simplify right side
   42,691.32x = 1,314,523,757.03
5. Step 5: Solve for x
   x = 1,314,523,757.03/42,691.32
6. Step 6: Final answer
   x = 30,791.36