Finding the Fourth Proportional to 92.79, 128.06 and 57.83

Step by Step Solution

1. Step 1: Write the proportion equation
   92.79 : 128.06 = 57.83 : x
2. Step 2: Convert to fraction form
   92.79/128.06 = 57.83/x
3. Step 3: Cross multiply
   92.79x = 128.06 × 57.83
4. Step 4: Simplify right side
   92.79x = 7,405.32
5. Step 5: Solve for x
   x = 7,405.32/92.79
6. Step 6: Final answer
   x = 79.81