Finding the Fourth Proportional to 123.77, 170.72 and 82.31

Step by Step Solution

1. Step 1: Write the proportion equation
   123.77 : 170.72 = 82.31 : x
2. Step 2: Convert to fraction form
   123.77/170.72 = 82.31/x
3. Step 3: Cross multiply
   123.77x = 170.72 × 82.31
4. Step 4: Simplify right side
   123.77x = 14,051.01
5. Step 5: Solve for x
   x = 14,051.01/123.77
6. Step 6: Final answer
   x = 113.52