Finding the Fourth Proportional to 1,116.45, 1,674.63 and 811.89

Step by Step Solution

1. Step 1: Write the proportion equation
   1,116.45 : 1,674.63 = 811.89 : x
2. Step 2: Convert to fraction form
   1,116.45/1,674.63 = 811.89/x
3. Step 3: Cross multiply
   1,116.45x = 1,674.63 × 811.89
4. Step 4: Simplify right side
   1,116.45x = 1,359,615.35
5. Step 5: Solve for x
   x = 1,359,615.35/1,116.45
6. Step 6: Final answer
   x = 1,217.80