Finding the Third Proportional to 289.56 and 426.72

Step by Step Solution

1. Step 1: Write the proportion equation
   289.56 : 426.72 = 426.72 : x
2. Step 2: Convert to fraction form
   289.56/426.72 = 426.72/x
3. Step 3: Cross multiply
   289.56x = 426.72 × 426.72
4. Step 4: Simplify right side
   289.56x = 182,088.89
5. Step 5: Solve for x
   x = 182,088.89/289.56
6. Step 6: Final answer
   x = 628.84