Finding the Fourth Proportional to 1,172.39, 1,617.81 and 648.38

Step by Step Solution

1. Step 1: Write the proportion equation
   1,172.39 : 1,617.81 = 648.38 : x
2. Step 2: Convert to fraction form
   1,172.39/1,617.81 = 648.38/x
3. Step 3: Cross multiply
   1,172.39x = 1,617.81 × 648.38
4. Step 4: Simplify right side
   1,172.39x = 1,048,947.56
5. Step 5: Solve for x
   x = 1,048,947.56/1,172.39
6. Step 6: Final answer
   x = 894.71