Finding the Fourth Proportional to 1,131.72, 1,561.77 and 659.89

Step by Step Solution

1. Step 1: Write the proportion equation
   1,131.72 : 1,561.77 = 659.89 : x
2. Step 2: Convert to fraction form
   1,131.72/1,561.77 = 659.89/x
3. Step 3: Cross multiply
   1,131.72x = 1,561.77 × 659.89
4. Step 4: Simplify right side
   1,131.72x = 1,030,596.41
5. Step 5: Solve for x
   x = 1,030,596.41/1,131.72
6. Step 6: Final answer
   x = 910.65