Finding the Fourth Proportional to 1,172.81, 1,618.49 and 648.86

Step by Step Solution

1. Step 1: Write the proportion equation
   1,172.81 : 1,618.49 = 648.86 : x
2. Step 2: Convert to fraction form
   1,172.81/1,618.49 = 648.86/x
3. Step 3: Cross multiply
   1,172.81x = 1,618.49 × 648.86
4. Step 4: Simplify right side
   1,172.81x = 1,050,166.95
5. Step 5: Solve for x
   x = 1,050,166.95/1,172.81
6. Step 6: Final answer
   x = 895.43