Finding the Fourth Proportional to 978.77, 1,347.39 and 757.31

Step by Step Solution

1. Step 1: Write the proportion equation
   978.77 : 1,347.39 = 757.31 : x
2. Step 2: Convert to fraction form
   978.77/1,347.39 = 757.31/x
3. Step 3: Cross multiply
   978.77x = 1,347.39 × 757.31
4. Step 4: Simplify right side
   978.77x = 1,020,385.18
5. Step 5: Solve for x
   x = 1,020,385.18/978.77
6. Step 6: Final answer
   x = 1,042.52