Finding the Fourth Proportional to 89.42, 133.98 and 78.46

Step by Step Solution

1. Step 1: Write the proportion equation
   89.42 : 133.98 = 78.46 : x
2. Step 2: Convert to fraction form
   89.42/133.98 = 78.46/x
3. Step 3: Cross multiply
   89.42x = 133.98 × 78.46
4. Step 4: Simplify right side
   89.42x = 10,512.07
5. Step 5: Solve for x
   x = 10,512.07/89.42
6. Step 6: Final answer
   x = 117.56