Finding the Fourth Proportional to 2,079.42, 3,119.61 and 780.89

Step by Step Solution

1. Step 1: Write the proportion equation
   2,079.42 : 3,119.61 = 780.89 : x
2. Step 2: Convert to fraction form
   2,079.42/3,119.61 = 780.89/x
3. Step 3: Cross multiply
   2,079.42x = 3,119.61 × 780.89
4. Step 4: Simplify right side
   2,079.42x = 2,436,077.13
5. Step 5: Solve for x
   x = 2,436,077.13/2,079.42
6. Step 6: Final answer
   x = 1,171.52