Finding the Fourth Proportional to 89.37, 134.58 and 78.09

Step by Step Solution

1. Step 1: Write the proportion equation
   89.37 : 134.58 = 78.09 : x
2. Step 2: Convert to fraction form
   89.37/134.58 = 78.09/x
3. Step 3: Cross multiply
   89.37x = 134.58 × 78.09
4. Step 4: Simplify right side
   89.37x = 10,509.35
5. Step 5: Solve for x
   x = 10,509.35/89.37
6. Step 6: Final answer
   x = 117.59