Finding the Third Proportional to 99.84 and 206.69

Step by Step Solution

1. Step 1: Write the proportion equation
   99.84 : 206.69 = 206.69 : x
2. Step 2: Convert to fraction form
   99.84/206.69 = 206.69/x
3. Step 3: Cross multiply
   99.84x = 206.69 × 206.69
4. Step 4: Simplify right side
   99.84x = 42,719.72
5. Step 5: Solve for x
   x = 42,719.72/99.84
6. Step 6: Final answer
   x = 427.87