Finding the Fourth Proportional to 978.61, 1,351.56 and 683.37

Step by Step Solution

1. Step 1: Write the proportion equation
   978.61 : 1,351.56 = 683.37 : x
2. Step 2: Convert to fraction form
   978.61/1,351.56 = 683.37/x
3. Step 3: Cross multiply
   978.61x = 1,351.56 × 683.37
4. Step 4: Simplify right side
   978.61x = 923,612.18
5. Step 5: Solve for x
   x = 923,612.18/978.61
6. Step 6: Final answer
   x = 943.80