Finding the Third Proportional to 100.31 and 109.31

Step by Step Solution

1. Step 1: Write the proportion equation
   100.31 : 109.31 = 109.31 : x
2. Step 2: Convert to fraction form
   100.31/109.31 = 109.31/x
3. Step 3: Cross multiply
   100.31x = 109.31 × 109.31
4. Step 4: Simplify right side
   100.31x = 11,949.22
5. Step 5: Solve for x
   x = 11,949.22/100.31
6. Step 6: Final answer
   x = 119.12