Finding the Fourth Proportional to 2,079.78, 2,870.36 and 1,240.83

Step by Step Solution

1. Step 1: Write the proportion equation
   2,079.78 : 2,870.36 = 1,240.83 : x
2. Step 2: Convert to fraction form
   2,079.78/2,870.36 = 1,240.83/x
3. Step 3: Cross multiply
   2,079.78x = 2,870.36 × 1,240.83
4. Step 4: Simplify right side
   2,079.78x = 3,561,622.59
5. Step 5: Solve for x
   x = 3,561,622.59/2,079.78
6. Step 6: Final answer
   x = 1,712.50