Finding the Third Proportional to 76.64 and 109.69

Step by Step Solution

1. Step 1: Write the proportion equation
   76.64 : 109.69 = 109.69 : x
2. Step 2: Convert to fraction form
   76.64/109.69 = 109.69/x
3. Step 3: Cross multiply
   76.64x = 109.69 × 109.69
4. Step 4: Simplify right side
   76.64x = 12,031.35
5. Step 5: Solve for x
   x = 12,031.35/76.64
6. Step 6: Final answer
   x = 156.98