Finding the Fourth Proportional to 1,171.98, 1,617.27 and 648

Step by Step Solution

1. Step 1: Write the proportion equation
   1,171.98 : 1,617.27 = 648 : x
2. Step 2: Convert to fraction form
   1,171.98/1,617.27 = 648/x
3. Step 3: Cross multiply
   1,171.98x = 1,617.27 × 648
4. Step 4: Simplify right side
   1,171.98x = 1,047,990.96
5. Step 5: Solve for x
   x = 1,047,990.96/1,171.98
6. Step 6: Final answer
   x = 894.21