Finding the Third Proportional to 289.41 and 611.72

Step by Step Solution

1. Step 1: Write the proportion equation
   289.41 : 611.72 = 611.72 : x
2. Step 2: Convert to fraction form
   289.41/611.72 = 611.72/x
3. Step 3: Cross multiply
   289.41x = 611.72 × 611.72
4. Step 4: Simplify right side
   289.41x = 374,199.83
5. Step 5: Solve for x
   x = 374,199.83/289.41
6. Step 6: Final answer
   x = 1,292.99