Finding the Fourth Proportional to 1,131.89, 1,563.22 and 778.74

Step by Step Solution

1. Step 1: Write the proportion equation
   1,131.89 : 1,563.22 = 778.74 : x
2. Step 2: Convert to fraction form
   1,131.89/1,563.22 = 778.74/x
3. Step 3: Cross multiply
   1,131.89x = 1,563.22 × 778.74
4. Step 4: Simplify right side
   1,131.89x = 1,217,341.94
5. Step 5: Solve for x
   x = 1,217,341.94/1,131.89
6. Step 6: Final answer
   x = 1,075.49