Finding the Fourth Proportional to 1,131.17, 1,561.28 and 689.41

Step by Step Solution

1. Step 1: Write the proportion equation
   1,131.17 : 1,561.28 = 689.41 : x
2. Step 2: Convert to fraction form
   1,131.17/1,561.28 = 689.41/x
3. Step 3: Cross multiply
   1,131.17x = 1,561.28 × 689.41
4. Step 4: Simplify right side
   1,131.17x = 1,076,360.55
5. Step 5: Solve for x
   x = 1,076,360.55/1,131.17
6. Step 6: Final answer
   x = 951.55