Finding the Fourth Proportional to 88.34, 131.82 and 78.55

Step by Step Solution

1. Step 1: Write the proportion equation
   88.34 : 131.82 = 78.55 : x
2. Step 2: Convert to fraction form
   88.34/131.82 = 78.55/x
3. Step 3: Cross multiply
   88.34x = 131.82 × 78.55
4. Step 4: Simplify right side
   88.34x = 10,353.41
5. Step 5: Solve for x
   x = 10,353.41/88.34
6. Step 6: Final answer
   x = 117.20