Finding the Fourth Proportional to 1,131.54, 1,561.03 and 711.60

Step by Step Solution

1. Step 1: Write the proportion equation
   1,131.54 : 1,561.03 = 711.60 : x
2. Step 2: Convert to fraction form
   1,131.54/1,561.03 = 711.60/x
3. Step 3: Cross multiply
   1,131.54x = 1,561.03 × 711.60
4. Step 4: Simplify right side
   1,131.54x = 1,110,828.95
5. Step 5: Solve for x
   x = 1,110,828.95/1,131.54
6. Step 6: Final answer
   x = 981.70