Finding the Fourth Proportional to 1,191.76, 1,785.31 and 820.69

Step by Step Solution

1. Step 1: Write the proportion equation
   1,191.76 : 1,785.31 = 820.69 : x
2. Step 2: Convert to fraction form
   1,191.76/1,785.31 = 820.69/x
3. Step 3: Cross multiply
   1,191.76x = 1,785.31 × 820.69
4. Step 4: Simplify right side
   1,191.76x = 1,465,179.55
5. Step 5: Solve for x
   x = 1,465,179.55/1,191.76
6. Step 6: Final answer
   x = 1,229.43