Finding the Fourth Proportional to 2,080.53, 3,118.40 and 780.69

Step by Step Solution

1. Step 1: Write the proportion equation
   2,080.53 : 3,118.40 = 780.69 : x
2. Step 2: Convert to fraction form
   2,080.53/3,118.40 = 780.69/x
3. Step 3: Cross multiply
   2,080.53x = 3,118.40 × 780.69
4. Step 4: Simplify right side
   2,080.53x = 2,434,499.79
5. Step 5: Solve for x
   x = 2,434,499.79/2,080.53
6. Step 6: Final answer
   x = 1,170.13