Finding the Fourth Proportional to 1,131.60, 1,561.51 and 689.42

Step by Step Solution

1. Step 1: Write the proportion equation
   1,131.60 : 1,561.51 = 689.42 : x
2. Step 2: Convert to fraction form
   1,131.60/1,561.51 = 689.42/x
3. Step 3: Cross multiply
   1,131.60x = 1,561.51 × 689.42
4. Step 4: Simplify right side
   1,131.60x = 1,076,538.40
5. Step 5: Solve for x
   x = 1,076,538.40/1,131.60
6. Step 6: Final answer
   x = 951.34