Finding the Fourth Proportional to 123.69, 170.59 and 80.09

Step by Step Solution

1. Step 1: Write the proportion equation
   123.69 : 170.59 = 80.09 : x
2. Step 2: Convert to fraction form
   123.69/170.59 = 80.09/x
3. Step 3: Cross multiply
   123.69x = 170.59 × 80.09
4. Step 4: Simplify right side
   123.69x = 13,662.55
5. Step 5: Solve for x
   x = 13,662.55/123.69
6. Step 6: Final answer
   x = 110.46