Finding the Fourth Proportional to 111.43, 153.61 and 78.58

Step by Step Solution

1. Step 1: Write the proportion equation
   111.43 : 153.61 = 78.58 : x
2. Step 2: Convert to fraction form
   111.43/153.61 = 78.58/x
3. Step 3: Cross multiply
   111.43x = 153.61 × 78.58
4. Step 4: Simplify right side
   111.43x = 12,070.67
5. Step 5: Solve for x
   x = 12,070.67/111.43
6. Step 6: Final answer
   x = 108.33