Finding the Third Proportional to 78.75 and 104.25

Step by Step Solution

1. Step 1: Write the proportion equation
   78.75 : 104.25 = 104.25 : x
2. Step 2: Convert to fraction form
   78.75/104.25 = 104.25/x
3. Step 3: Cross multiply
   78.75x = 104.25 × 104.25
4. Step 4: Simplify right side
   78.75x = 10,868.06
5. Step 5: Solve for x
   x = 10,868.06/78.75
6. Step 6: Final answer
   x = 138.01