Finding the Fourth Proportional to 3,690.18, 5,085.45 and 2,640.42

Step by Step Solution

1. Step 1: Write the proportion equation
   3,690.18 : 5,085.45 = 2,640.42 : x
2. Step 2: Convert to fraction form
   3,690.18/5,085.45 = 2,640.42/x
3. Step 3: Cross multiply
   3,690.18x = 5,085.45 × 2,640.42
4. Step 4: Simplify right side
   3,690.18x = 13,427,723.89
5. Step 5: Solve for x
   x = 13,427,723.89/3,690.18
6. Step 6: Final answer
   x = 3,638.77