Finding the Fourth Proportional to 111.71, 153.90 and 82.55

Step by Step Solution

1. Step 1: Write the proportion equation
   111.71 : 153.90 = 82.55 : x
2. Step 2: Convert to fraction form
   111.71/153.90 = 82.55/x
3. Step 3: Cross multiply
   111.71x = 153.90 × 82.55
4. Step 4: Simplify right side
   111.71x = 12,704.83
5. Step 5: Solve for x
   x = 12,704.83/111.71
6. Step 6: Final answer
   x = 113.73