Finding the Fourth Proportional to 1,109.28, 1,530.72 and 611.90

Step by Step Solution

1. Step 1: Write the proportion equation
   1,109.28 : 1,530.72 = 611.90 : x
2. Step 2: Convert to fraction form
   1,109.28/1,530.72 = 611.90/x
3. Step 3: Cross multiply
   1,109.28x = 1,530.72 × 611.90
4. Step 4: Simplify right side
   1,109.28x = 936,647.57
5. Step 5: Solve for x
   x = 936,647.57/1,109.28
6. Step 6: Final answer
   x = 844.37