Finding the Third Proportional to 290.25 and 435.56

Step by Step Solution

1. Step 1: Write the proportion equation
   290.25 : 435.56 = 435.56 : x
2. Step 2: Convert to fraction form
   290.25/435.56 = 435.56/x
3. Step 3: Cross multiply
   290.25x = 435.56 × 435.56
4. Step 4: Simplify right side
   290.25x = 189,714.69
5. Step 5: Solve for x
   x = 189,714.69/290.25
6. Step 6: Final answer
   x = 653.63