Finding the Fourth Proportional to 1,224.72, 1,690.16 and 672.72

Step by Step Solution

1. Step 1: Write the proportion equation
   1,224.72 : 1,690.16 = 672.72 : x
2. Step 2: Convert to fraction form
   1,224.72/1,690.16 = 672.72/x
3. Step 3: Cross multiply
   1,224.72x = 1,690.16 × 672.72
4. Step 4: Simplify right side
   1,224.72x = 1,137,004.44
5. Step 5: Solve for x
   x = 1,137,004.44/1,224.72
6. Step 6: Final answer
   x = 928.38