Finding the Fourth Proportional to 978.71, 1,469.42 and 648.68

Step by Step Solution

1. Step 1: Write the proportion equation
   978.71 : 1,469.42 = 648.68 : x
2. Step 2: Convert to fraction form
   978.71/1,469.42 = 648.68/x
3. Step 3: Cross multiply
   978.71x = 1,469.42 × 648.68
4. Step 4: Simplify right side
   978.71x = 953,172.78
5. Step 5: Solve for x
   x = 953,172.78/978.71
6. Step 6: Final answer
   x = 973.91