Finding the Third Proportional to 561.94 and 620.72

Step by Step Solution

1. Step 1: Write the proportion equation
   561.94 : 620.72 = 620.72 : x
2. Step 2: Convert to fraction form
   561.94/620.72 = 620.72/x
3. Step 3: Cross multiply
   561.94x = 620.72 × 620.72
4. Step 4: Simplify right side
   561.94x = 385,291.77
5. Step 5: Solve for x
   x = 385,291.77/561.94
6. Step 6: Final answer
   x = 685.65