Finding the Third Proportional to 489.80 and 746.72

Step by Step Solution

1. Step 1: Write the proportion equation
   489.80 : 746.72 = 746.72 : x
2. Step 2: Convert to fraction form
   489.80/746.72 = 746.72/x
3. Step 3: Cross multiply
   489.80x = 746.72 × 746.72
4. Step 4: Simplify right side
   489.80x = 557,588.89
5. Step 5: Solve for x
   x = 557,588.89/489.80
6. Step 6: Final answer
   x = 1,138.41