Finding the Fourth Proportional to 1,042.47, 1,438.41 and 710.78

Step by Step Solution

1. Step 1: Write the proportion equation
   1,042.47 : 1,438.41 = 710.78 : x
2. Step 2: Convert to fraction form
   1,042.47/1,438.41 = 710.78/x
3. Step 3: Cross multiply
   1,042.47x = 1,438.41 × 710.78
4. Step 4: Simplify right side
   1,042.47x = 1,022,384.54
5. Step 5: Solve for x
   x = 1,022,384.54/1,042.47
6. Step 6: Final answer
   x = 980.73