Finding the Fourth Proportional to 2,485.72, 3,728.34 and 842.24

Step by Step Solution

1. Step 1: Write the proportion equation
   2,485.72 : 3,728.34 = 842.24 : x
2. Step 2: Convert to fraction form
   2,485.72/3,728.34 = 842.24/x
3. Step 3: Cross multiply
   2,485.72x = 3,728.34 × 842.24
4. Step 4: Simplify right side
   2,485.72x = 3,140,157.08
5. Step 5: Solve for x
   x = 3,140,157.08/2,485.72
6. Step 6: Final answer
   x = 1,263.28