Finding the Fourth Proportional to 1,172.79, 1,618.41 and 648.81

Step by Step Solution

1. Step 1: Write the proportion equation
   1,172.79 : 1,618.41 = 648.81 : x
2. Step 2: Convert to fraction form
   1,172.79/1,618.41 = 648.81/x
3. Step 3: Cross multiply
   1,172.79x = 1,618.41 × 648.81
4. Step 4: Simplify right side
   1,172.79x = 1,050,040.59
5. Step 5: Solve for x
   x = 1,050,040.59/1,172.79
6. Step 6: Final answer
   x = 895.34