Finding the Fourth Proportional to 2,690.24, 4,033.52 and 840.72

Step by Step Solution

1. Step 1: Write the proportion equation
   2,690.24 : 4,033.52 = 840.72 : x
2. Step 2: Convert to fraction form
   2,690.24/4,033.52 = 840.72/x
3. Step 3: Cross multiply
   2,690.24x = 4,033.52 × 840.72
4. Step 4: Simplify right side
   2,690.24x = 3,391,060.93
5. Step 5: Solve for x
   x = 3,391,060.93/2,690.24
6. Step 6: Final answer
   x = 1,260.50