Finding the Third Proportional to 76.89 and 170.86

Step by Step Solution

1. Step 1: Write the proportion equation
   76.89 : 170.86 = 170.86 : x
2. Step 2: Convert to fraction form
   76.89/170.86 = 170.86/x
3. Step 3: Cross multiply
   76.89x = 170.86 × 170.86
4. Step 4: Simplify right side
   76.89x = 29,192.93
5. Step 5: Solve for x
   x = 29,192.93/76.89
6. Step 6: Final answer
   x = 379.69