Finding the Fourth Proportional to 89.43, 123.35 and 85.55

Step by Step Solution

1. Step 1: Write the proportion equation
   89.43 : 123.35 = 85.55 : x
2. Step 2: Convert to fraction form
   89.43/123.35 = 85.55/x
3. Step 3: Cross multiply
   89.43x = 123.35 × 85.55
4. Step 4: Simplify right side
   89.43x = 10,551.55
5. Step 5: Solve for x
   x = 10,551.55/89.43
6. Step 6: Final answer
   x = 117.99