Finding the Fourth Proportional to 42,789.28, 64,145.04 and 19,402.96

Step by Step Solution

1. Step 1: Write the proportion equation
   42,789.28 : 64,145.04 = 19,402.96 : x
2. Step 2: Convert to fraction form
   42,789.28/64,145.04 = 19,402.96/x
3. Step 3: Cross multiply
   42,789.28x = 64,145.04 × 19,402.96
4. Step 4: Simplify right side
   42,789.28x = 1,244,603,645.32
5. Step 5: Solve for x
   x = 1,244,603,645.32/42,789.28
6. Step 6: Final answer
   x = 29,086.81