Finding the Fourth Proportional to 85.49, 128.31 and 59.82

Step by Step Solution

1. Step 1: Write the proportion equation
   85.49 : 128.31 = 59.82 : x
2. Step 2: Convert to fraction form
   85.49/128.31 = 59.82/x
3. Step 3: Cross multiply
   85.49x = 128.31 × 59.82
4. Step 4: Simplify right side
   85.49x = 7,675.50
5. Step 5: Solve for x
   x = 7,675.50/85.49
6. Step 6: Final answer
   x = 89.79