Finding the Fourth Proportional to 85.76, 128.67 and 27.98

Step by Step Solution

1. Step 1: Write the proportion equation
   85.76 : 128.67 = 27.98 : x
2. Step 2: Convert to fraction form
   85.76/128.67 = 27.98/x
3. Step 3: Cross multiply
   85.76x = 128.67 × 27.98
4. Step 4: Simplify right side
   85.76x = 3,600.51
5. Step 5: Solve for x
   x = 3,600.51/85.76
6. Step 6: Final answer
   x = 41.98