Finding the Fourth Proportional to 42,659.28, 64,023.12 and 19,287.72

Step by Step Solution

1. Step 1: Write the proportion equation
   42,659.28 : 64,023.12 = 19,287.72 : x
2. Step 2: Convert to fraction form
   42,659.28/64,023.12 = 19,287.72/x
3. Step 3: Cross multiply
   42,659.28x = 64,023.12 × 19,287.72
4. Step 4: Simplify right side
   42,659.28x = 1,234,860,012.09
5. Step 5: Solve for x
   x = 1,234,860,012.09/42,659.28
6. Step 6: Final answer
   x = 28,947.04