Finding the Third Proportional to 101.88 and 256.61

Step by Step Solution

1. Step 1: Write the proportion equation
   101.88 : 256.61 = 256.61 : x
2. Step 2: Convert to fraction form
   101.88/256.61 = 256.61/x
3. Step 3: Cross multiply
   101.88x = 256.61 × 256.61
4. Step 4: Simplify right side
   101.88x = 65,846.37
5. Step 5: Solve for x
   x = 65,846.37/101.88
6. Step 6: Final answer
   x = 646.30