Finding the Third Proportional to 11.88 and 15.31

Step by Step Solution

1. Step 1: Write the proportion equation
   11.88 : 15.31 = 15.31 : x
2. Step 2: Convert to fraction form
   11.88/15.31 = 15.31/x
3. Step 3: Cross multiply
   11.88x = 15.31 × 15.31
4. Step 4: Simplify right side
   11.88x = 234.47
5. Step 5: Solve for x
   x = 234.47/11.88
6. Step 6: Final answer
   x = 19.75