Finding the Fourth Proportional to 111.30, 166.59 and 84.15

Step by Step Solution

1. Step 1: Write the proportion equation
   111.30 : 166.59 = 84.15 : x
2. Step 2: Convert to fraction form
   111.30/166.59 = 84.15/x
3. Step 3: Cross multiply
   111.30x = 166.59 × 84.15
4. Step 4: Simplify right side
   111.30x = 14,018.55
5. Step 5: Solve for x
   x = 14,018.55/111.30
6. Step 6: Final answer
   x = 125.95