Finding the Fourth Proportional to 42,878.51, 64,283.41 and 20,377.89

Step by Step Solution

1. Step 1: Write the proportion equation
   42,878.51 : 64,283.41 = 20,377.89 : x
2. Step 2: Convert to fraction form
   42,878.51/64,283.41 = 20,377.89/x
3. Step 3: Cross multiply
   42,878.51x = 64,283.41 × 20,377.89
4. Step 4: Simplify right side
   42,878.51x = 1,309,960,340.59
5. Step 5: Solve for x
   x = 1,309,960,340.59/42,878.51
6. Step 6: Final answer
   x = 30,550.51