Finding the Fourth Proportional to 2,080.61, 3,120.69 and 782.18

Step by Step Solution

1. Step 1: Write the proportion equation
   2,080.61 : 3,120.69 = 782.18 : x
2. Step 2: Convert to fraction form
   2,080.61/3,120.69 = 782.18/x
3. Step 3: Cross multiply
   2,080.61x = 3,120.69 × 782.18
4. Step 4: Simplify right side
   2,080.61x = 2,440,925.70
5. Step 5: Solve for x
   x = 2,440,925.70/2,080.61
6. Step 6: Final answer
   x = 1,173.18