Finding the Third Proportional to 436.50 and 611.81

Step by Step Solution

1. Step 1: Write the proportion equation
   436.50 : 611.81 = 611.81 : x
2. Step 2: Convert to fraction form
   436.50/611.81 = 611.81/x
3. Step 3: Cross multiply
   436.50x = 611.81 × 611.81
4. Step 4: Simplify right side
   436.50x = 374,314.54
5. Step 5: Solve for x
   x = 374,314.54/436.50
6. Step 6: Final answer
   x = 857.54