Finding the Fourth Proportional to 89.83, 123.96 and 57.09

Step by Step Solution

1. Step 1: Write the proportion equation
   89.83 : 123.96 = 57.09 : x
2. Step 2: Convert to fraction form
   89.83/123.96 = 57.09/x
3. Step 3: Cross multiply
   89.83x = 123.96 × 57.09
4. Step 4: Simplify right side
   89.83x = 7,076.88
5. Step 5: Solve for x
   x = 7,076.88/89.83
6. Step 6: Final answer
   x = 78.78