Finding the Fourth Proportional to 1,172.91, 1,618.61 and 648.94

Step by Step Solution

1. Step 1: Write the proportion equation
   1,172.91 : 1,618.61 = 648.94 : x
2. Step 2: Convert to fraction form
   1,172.91/1,618.61 = 648.94/x
3. Step 3: Cross multiply
   1,172.91x = 1,618.61 × 648.94
4. Step 4: Simplify right side
   1,172.91x = 1,050,376.73
5. Step 5: Solve for x
   x = 1,050,376.73/1,172.91
6. Step 6: Final answer
   x = 895.53