Finding the Fourth Proportional to 123.05, 169.71 and 79.31

Step by Step Solution

1. Step 1: Write the proportion equation
   123.05 : 169.71 = 79.31 : x
2. Step 2: Convert to fraction form
   123.05/169.71 = 79.31/x
3. Step 3: Cross multiply
   123.05x = 169.71 × 79.31
4. Step 4: Simplify right side
   123.05x = 13,459.70
5. Step 5: Solve for x
   x = 13,459.70/123.05
6. Step 6: Final answer
   x = 109.38