Finding the Fourth Proportional to 111.10, 153.31 and 61.31

Step by Step Solution

1. Step 1: Write the proportion equation
   111.10 : 153.31 = 61.31 : x
2. Step 2: Convert to fraction form
   111.10/153.31 = 61.31/x
3. Step 3: Cross multiply
   111.10x = 153.31 × 61.31
4. Step 4: Simplify right side
   111.10x = 9,398.67
5. Step 5: Solve for x
   x = 9,398.67/111.10
6. Step 6: Final answer
   x = 84.60