Finding the Fourth Proportional to 42,735.96, 64,145.25 and 20,564.64

Step by Step Solution

1. Step 1: Write the proportion equation
   42,735.96 : 64,145.25 = 20,564.64 : x
2. Step 2: Convert to fraction form
   42,735.96/64,145.25 = 20,564.64/x
3. Step 3: Cross multiply
   42,735.96x = 64,145.25 × 20,564.64
4. Step 4: Simplify right side
   42,735.96x = 1,319,123,973.96
5. Step 5: Solve for x
   x = 1,319,123,973.96/42,735.96
6. Step 6: Final answer
   x = 30,866.84