Finding the Fourth Proportional to 111.32, 153.70 and 78.22

Step by Step Solution

1. Step 1: Write the proportion equation
   111.32 : 153.70 = 78.22 : x
2. Step 2: Convert to fraction form
   111.32/153.70 = 78.22/x
3. Step 3: Cross multiply
   111.32x = 153.70 × 78.22
4. Step 4: Simplify right side
   111.32x = 12,021.55
5. Step 5: Solve for x
   x = 12,021.55/111.32
6. Step 6: Final answer
   x = 107.99