Finding the Fourth Proportional to 1,172.48, 1,617.90 and 648.50

Step by Step Solution

1. Step 1: Write the proportion equation
   1,172.48 : 1,617.90 = 648.50 : x
2. Step 2: Convert to fraction form
   1,172.48/1,617.90 = 648.50/x
3. Step 3: Cross multiply
   1,172.48x = 1,617.90 × 648.50
4. Step 4: Simplify right side
   1,172.48x = 1,049,208.15
5. Step 5: Solve for x
   x = 1,049,208.15/1,172.48
6. Step 6: Final answer
   x = 894.86