Finding the Fourth Proportional to 830.27, 1,139.11 and 808.72

Step by Step Solution

1. Step 1: Write the proportion equation
   830.27 : 1,139.11 = 808.72 : x
2. Step 2: Convert to fraction form
   830.27/1,139.11 = 808.72/x
3. Step 3: Cross multiply
   830.27x = 1,139.11 × 808.72
4. Step 4: Simplify right side
   830.27x = 921,216.17
5. Step 5: Solve for x
   x = 921,216.17/830.27
6. Step 6: Final answer
   x = 1,109.53