Finding the Fourth Proportional to 85.72, 128.52 and 59.68

Step by Step Solution

1. Step 1: Write the proportion equation
   85.72 : 128.52 = 59.68 : x
2. Step 2: Convert to fraction form
   85.72/128.52 = 59.68/x
3. Step 3: Cross multiply
   85.72x = 128.52 × 59.68
4. Step 4: Simplify right side
   85.72x = 7,670.07
5. Step 5: Solve for x
   x = 7,670.07/85.72
6. Step 6: Final answer
   x = 89.48