Finding the Fourth Proportional to 89.49, 123.23 and 85.80

Step by Step Solution

1. Step 1: Write the proportion equation
   89.49 : 123.23 = 85.80 : x
2. Step 2: Convert to fraction form
   89.49/123.23 = 85.80/x
3. Step 3: Cross multiply
   89.49x = 123.23 × 85.80
4. Step 4: Simplify right side
   89.49x = 10,572.78
5. Step 5: Solve for x
   x = 10,572.78/89.49
6. Step 6: Final answer
   x = 118.14