Finding the Fourth Proportional to 2,613.98, 3,920.94 and 666.18

Step by Step Solution

1. Step 1: Write the proportion equation
   2,613.98 : 3,920.94 = 666.18 : x
2. Step 2: Convert to fraction form
   2,613.98/3,920.94 = 666.18/x
3. Step 3: Cross multiply
   2,613.98x = 3,920.94 × 666.18
4. Step 4: Simplify right side
   2,613.98x = 2,612,051.81
5. Step 5: Solve for x
   x = 2,612,051.81/2,613.98
6. Step 6: Final answer
   x = 999.26