Finding the Fourth Proportional to 1,609.69, 2,221.78 and 911.47

Step by Step Solution

1. Step 1: Write the proportion equation
   1,609.69 : 2,221.78 = 911.47 : x
2. Step 2: Convert to fraction form
   1,609.69/2,221.78 = 911.47/x
3. Step 3: Cross multiply
   1,609.69x = 2,221.78 × 911.47
4. Step 4: Simplify right side
   1,609.69x = 2,025,085.82
5. Step 5: Solve for x
   x = 2,025,085.82/1,609.69
6. Step 6: Final answer
   x = 1,258.06