Finding the Fourth Proportional to 2,665.59, 3,998.58 and 909.89

Step by Step Solution

1. Step 1: Write the proportion equation
   2,665.59 : 3,998.58 = 909.89 : x
2. Step 2: Convert to fraction form
   2,665.59/3,998.58 = 909.89/x
3. Step 3: Cross multiply
   2,665.59x = 3,998.58 × 909.89
4. Step 4: Simplify right side
   2,665.59x = 3,638,267.96
5. Step 5: Solve for x
   x = 3,638,267.96/2,665.59
6. Step 6: Final answer
   x = 1,364.90