Finding the Third Proportional to 420.75 and 561.38

Step by Step Solution

1. Step 1: Write the proportion equation
   420.75 : 561.38 = 561.38 : x
2. Step 2: Convert to fraction form
   420.75/561.38 = 561.38/x
3. Step 3: Cross multiply
   420.75x = 561.38 × 561.38
4. Step 4: Simplify right side
   420.75x = 315,141.89
5. Step 5: Solve for x
   x = 315,141.89/420.75
6. Step 6: Final answer
   x = 749.00