Finding the Third Proportional to 123.75 and 291.75

Step by Step Solution

1. Step 1: Write the proportion equation
   123.75 : 291.75 = 291.75 : x
2. Step 2: Convert to fraction form
   123.75/291.75 = 291.75/x
3. Step 3: Cross multiply
   123.75x = 291.75 × 291.75
4. Step 4: Simplify right side
   123.75x = 85,118.06
5. Step 5: Solve for x
   x = 85,118.06/123.75
6. Step 6: Final answer
   x = 687.82