Finding the Fourth Proportional to 2,116.40, 3,174.56 and 817.12

Step by Step Solution

1. Step 1: Write the proportion equation
   2,116.40 : 3,174.56 = 817.12 : x
2. Step 2: Convert to fraction form
   2,116.40/3,174.56 = 817.12/x
3. Step 3: Cross multiply
   2,116.40x = 3,174.56 × 817.12
4. Step 4: Simplify right side
   2,116.40x = 2,593,996.47
5. Step 5: Solve for x
   x = 2,593,996.47/2,116.40
6. Step 6: Final answer
   x = 1,225.66