Finding the Fourth Proportional to 89.75, 134.37 and 78.12

Step by Step Solution

1. Step 1: Write the proportion equation
   89.75 : 134.37 = 78.12 : x
2. Step 2: Convert to fraction form
   89.75/134.37 = 78.12/x
3. Step 3: Cross multiply
   89.75x = 134.37 × 78.12
4. Step 4: Simplify right side
   89.75x = 10,496.98
5. Step 5: Solve for x
   x = 10,496.98/89.75
6. Step 6: Final answer
   x = 116.96