Finding the Fourth Proportional to 2,080.57, 2,870.75 and 1,218.05

Step by Step Solution

1. Step 1: Write the proportion equation
   2,080.57 : 2,870.75 = 1,218.05 : x
2. Step 2: Convert to fraction form
   2,080.57/2,870.75 = 1,218.05/x
3. Step 3: Cross multiply
   2,080.57x = 2,870.75 × 1,218.05
4. Step 4: Simplify right side
   2,080.57x = 3,496,710.95
5. Step 5: Solve for x
   x = 3,496,710.95/2,080.57
6. Step 6: Final answer
   x = 1,680.65