Finding the Third Proportional to 390.56 and 469.69

Step by Step Solution

1. Step 1: Write the proportion equation
   390.56 : 469.69 = 469.69 : x
2. Step 2: Convert to fraction form
   390.56/469.69 = 469.69/x
3. Step 3: Cross multiply
   390.56x = 469.69 × 469.69
4. Step 4: Simplify right side
   390.56x = 220,606.35
5. Step 5: Solve for x
   x = 220,606.35/390.56
6. Step 6: Final answer
   x = 564.84