Finding the Third Proportional to 310.78 and 429.61

Step by Step Solution

1. Step 1: Write the proportion equation
   310.78 : 429.61 = 429.61 : x
2. Step 2: Convert to fraction form
   310.78/429.61 = 429.61/x
3. Step 3: Cross multiply
   310.78x = 429.61 × 429.61
4. Step 4: Simplify right side
   310.78x = 184,564.22
5. Step 5: Solve for x
   x = 184,564.22/310.78
6. Step 6: Final answer
   x = 593.87