Finding the Fourth Proportional to 111.31, 153.46 and 78.07

Step by Step Solution

1. Step 1: Write the proportion equation
   111.31 : 153.46 = 78.07 : x
2. Step 2: Convert to fraction form
   111.31/153.46 = 78.07/x
3. Step 3: Cross multiply
   111.31x = 153.46 × 78.07
4. Step 4: Simplify right side
   111.31x = 11,980.84
5. Step 5: Solve for x
   x = 11,980.84/111.31
6. Step 6: Final answer
   x = 107.63