Finding the Fourth Proportional to 2,613.10, 3,919.78 and 665.32

Step by Step Solution

1. Step 1: Write the proportion equation
   2,613.10 : 3,919.78 = 665.32 : x
2. Step 2: Convert to fraction form
   2,613.10/3,919.78 = 665.32/x
3. Step 3: Cross multiply
   2,613.10x = 3,919.78 × 665.32
4. Step 4: Simplify right side
   2,613.10x = 2,607,908.03
5. Step 5: Solve for x
   x = 2,607,908.03/2,613.10
6. Step 6: Final answer
   x = 998.01