Finding the Fourth Proportional to 111.02, 166.18 and 78.48

Step by Step Solution

1. Step 1: Write the proportion equation
   111.02 : 166.18 = 78.48 : x
2. Step 2: Convert to fraction form
   111.02/166.18 = 78.48/x
3. Step 3: Cross multiply
   111.02x = 166.18 × 78.48
4. Step 4: Simplify right side
   111.02x = 13,041.81
5. Step 5: Solve for x
   x = 13,041.81/111.02
6. Step 6: Final answer
   x = 117.47