Finding the Third Proportional to 291.38 and 448.31

Step by Step Solution

1. Step 1: Write the proportion equation
   291.38 : 448.31 = 448.31 : x
2. Step 2: Convert to fraction form
   291.38/448.31 = 448.31/x
3. Step 3: Cross multiply
   291.38x = 448.31 × 448.31
4. Step 4: Simplify right side
   291.38x = 200,984.10
5. Step 5: Solve for x
   x = 200,984.10/291.38
6. Step 6: Final answer
   x = 689.78