Finding the Fourth Proportional to 1,131.06, 1,561.77 and 909.30

Step by Step Solution

1. Step 1: Write the proportion equation
   1,131.06 : 1,561.77 = 909.30 : x
2. Step 2: Convert to fraction form
   1,131.06/1,561.77 = 909.30/x
3. Step 3: Cross multiply
   1,131.06x = 1,561.77 × 909.30
4. Step 4: Simplify right side
   1,131.06x = 1,420,117.46
5. Step 5: Solve for x
   x = 1,420,117.46/1,131.06
6. Step 6: Final answer
   x = 1,255.56