Finding the Fourth Proportional to 42,781, 64,078.04 and 21,684.80

Step by Step Solution

1. Step 1: Write the proportion equation
   42,781 : 64,078.04 = 21,684.80 : x
2. Step 2: Convert to fraction form
   42,781/64,078.04 = 21,684.80/x
3. Step 3: Cross multiply
   42,781x = 64,078.04 × 21,684.80
4. Step 4: Simplify right side
   42,781x = 1,389,519,481.79
5. Step 5: Solve for x
   x = 1,389,519,481.79/42,781
6. Step 6: Final answer
   x = 32,479.83