Finding the Fourth Proportional to 111.86, 154.37 and 84.18

Step by Step Solution

1. Step 1: Write the proportion equation
   111.86 : 154.37 = 84.18 : x
2. Step 2: Convert to fraction form
   111.86/154.37 = 84.18/x
3. Step 3: Cross multiply
   111.86x = 154.37 × 84.18
4. Step 4: Simplify right side
   111.86x = 12,994.87
5. Step 5: Solve for x
   x = 12,994.87/111.86
6. Step 6: Final answer
   x = 116.17