Finding the Fourth Proportional to 1,172.31, 1,617.77 and 648.35

Step by Step Solution

1. Step 1: Write the proportion equation
   1,172.31 : 1,617.77 = 648.35 : x
2. Step 2: Convert to fraction form
   1,172.31/1,617.77 = 648.35/x
3. Step 3: Cross multiply
   1,172.31x = 1,617.77 × 648.35
4. Step 4: Simplify right side
   1,172.31x = 1,048,869.85
5. Step 5: Solve for x
   x = 1,048,869.85/1,172.31
6. Step 6: Final answer
   x = 894.70