Finding the Fourth Proportional to 1,131.12, 1,560.30 and 776.76

Step by Step Solution

1. Step 1: Write the proportion equation
   1,131.12 : 1,560.30 = 776.76 : x
2. Step 2: Convert to fraction form
   1,131.12/1,560.30 = 776.76/x
3. Step 3: Cross multiply
   1,131.12x = 1,560.30 × 776.76
4. Step 4: Simplify right side
   1,131.12x = 1,211,978.63
5. Step 5: Solve for x
   x = 1,211,978.63/1,131.12
6. Step 6: Final answer
   x = 1,071.49