Finding the Fourth Proportional to 1,131.30, 1,561.68 and 689.58

Step by Step Solution

1. Step 1: Write the proportion equation
   1,131.30 : 1,561.68 = 689.58 : x
2. Step 2: Convert to fraction form
   1,131.30/1,561.68 = 689.58/x
3. Step 3: Cross multiply
   1,131.30x = 1,561.68 × 689.58
4. Step 4: Simplify right side
   1,131.30x = 1,076,903.29
5. Step 5: Solve for x
   x = 1,076,903.29/1,131.30
6. Step 6: Final answer
   x = 951.92