Finding the Fourth Proportional to 1,172.63, 1,618.25 and 648.65

Step by Step Solution

1. Step 1: Write the proportion equation
   1,172.63 : 1,618.25 = 648.65 : x
2. Step 2: Convert to fraction form
   1,172.63/1,618.25 = 648.65/x
3. Step 3: Cross multiply
   1,172.63x = 1,618.25 × 648.65
4. Step 4: Simplify right side
   1,172.63x = 1,049,677.86
5. Step 5: Solve for x
   x = 1,049,677.86/1,172.63
6. Step 6: Final answer
   x = 895.15