Finding the Fourth Proportional to 42,911.28, 64,350.72 and 20,717.28

Step by Step Solution

1. Step 1: Write the proportion equation
   42,911.28 : 64,350.72 = 20,717.28 : x
2. Step 2: Convert to fraction form
   42,911.28/64,350.72 = 20,717.28/x
3. Step 3: Cross multiply
   42,911.28x = 64,350.72 × 20,717.28
4. Step 4: Simplify right side
   42,911.28x = 1,333,171,884.44
5. Step 5: Solve for x
   x = 1,333,171,884.44/42,911.28
6. Step 6: Final answer
   x = 31,068.10