Finding the Fourth Proportional to 1,609.08, 2,220.42 and 900.89

Step by Step Solution

1. Step 1: Write the proportion equation
   1,609.08 : 2,220.42 = 900.89 : x
2. Step 2: Convert to fraction form
   1,609.08/2,220.42 = 900.89/x
3. Step 3: Cross multiply
   1,609.08x = 2,220.42 × 900.89
4. Step 4: Simplify right side
   1,609.08x = 2,000,359.72
5. Step 5: Solve for x
   x = 2,000,359.72/1,609.08
6. Step 6: Final answer
   x = 1,243.17