Finding the Fourth Proportional to 2,167.28, 2,990.72 and 1,223.02

Step by Step Solution

1. Step 1: Write the proportion equation
   2,167.28 : 2,990.72 = 1,223.02 : x
2. Step 2: Convert to fraction form
   2,167.28/2,990.72 = 1,223.02/x
3. Step 3: Cross multiply
   2,167.28x = 2,990.72 × 1,223.02
4. Step 4: Simplify right side
   2,167.28x = 3,657,695.42
5. Step 5: Solve for x
   x = 3,657,695.42/2,167.28
6. Step 6: Final answer
   x = 1,687.69