Finding the Fourth Proportional to 42,800.47, 64,215.86 and 19,105.81

Step by Step Solution

1. Step 1: Write the proportion equation
   42,800.47 : 64,215.86 = 19,105.81 : x
2. Step 2: Convert to fraction form
   42,800.47/64,215.86 = 19,105.81/x
3. Step 3: Cross multiply
   42,800.47x = 64,215.86 × 19,105.81
4. Step 4: Simplify right side
   42,800.47x = 1,226,895,764.08
5. Step 5: Solve for x
   x = 1,226,895,764.08/42,800.47
6. Step 6: Final answer
   x = 28,665.48