Finding the Fourth Proportional to 2,080.14, 3,119.16 and 780.72

Step by Step Solution

1. Step 1: Write the proportion equation
   2,080.14 : 3,119.16 = 780.72 : x
2. Step 2: Convert to fraction form
   2,080.14/3,119.16 = 780.72/x
3. Step 3: Cross multiply
   2,080.14x = 3,119.16 × 780.72
4. Step 4: Simplify right side
   2,080.14x = 2,435,190.60
5. Step 5: Solve for x
   x = 2,435,190.60/2,080.14
6. Step 6: Final answer
   x = 1,170.69