Finding the Fourth Proportional to 2,789.98, 4,185.54 and 842.20

Step by Step Solution

1. Step 1: Write the proportion equation
   2,789.98 : 4,185.54 = 842.20 : x
2. Step 2: Convert to fraction form
   2,789.98/4,185.54 = 842.20/x
3. Step 3: Cross multiply
   2,789.98x = 4,185.54 × 842.20
4. Step 4: Simplify right side
   2,789.98x = 3,525,061.79
5. Step 5: Solve for x
   x = 3,525,061.79/2,789.98
6. Step 6: Final answer
   x = 1,263.47