Finding the Fourth Proportional to 1,118.38, 1,543.98 and 782.80

Step by Step Solution

1. Step 1: Write the proportion equation
   1,118.38 : 1,543.98 = 782.80 : x
2. Step 2: Convert to fraction form
   1,118.38/1,543.98 = 782.80/x
3. Step 3: Cross multiply
   1,118.38x = 1,543.98 × 782.80
4. Step 4: Simplify right side
   1,118.38x = 1,208,627.54
5. Step 5: Solve for x
   x = 1,208,627.54/1,118.38
6. Step 6: Final answer
   x = 1,080.69