Finding the Fourth Proportional to 111.83, 154.31 and 63.91

Step by Step Solution

1. Step 1: Write the proportion equation
   111.83 : 154.31 = 63.91 : x
2. Step 2: Convert to fraction form
   111.83/154.31 = 63.91/x
3. Step 3: Cross multiply
   111.83x = 154.31 × 63.91
4. Step 4: Simplify right side
   111.83x = 9,861.18
5. Step 5: Solve for x
   x = 9,861.18/111.83
6. Step 6: Final answer
   x = 88.18