Finding the Fourth Proportional to 111.61, 166.49 and 100.07

Step by Step Solution

1. Step 1: Write the proportion equation
   111.61 : 166.49 = 100.07 : x
2. Step 2: Convert to fraction form
   111.61/166.49 = 100.07/x
3. Step 3: Cross multiply
   111.61x = 166.49 × 100.07
4. Step 4: Simplify right side
   111.61x = 16,660.32
5. Step 5: Solve for x
   x = 16,660.32/111.61
6. Step 6: Final answer
   x = 149.27