Finding the Fourth Proportional to 2,585.58, 3,878.16 and 830.76

Step by Step Solution

1. Step 1: Write the proportion equation
   2,585.58 : 3,878.16 = 830.76 : x
2. Step 2: Convert to fraction form
   2,585.58/3,878.16 = 830.76/x
3. Step 3: Cross multiply
   2,585.58x = 3,878.16 × 830.76
4. Step 4: Simplify right side
   2,585.58x = 3,221,820.20
5. Step 5: Solve for x
   x = 3,221,820.20/2,585.58
6. Step 6: Final answer
   x = 1,246.07