Finding the Fourth Proportional to 89.80, 123.54 and 88.12

Step by Step Solution

1. Step 1: Write the proportion equation
   89.80 : 123.54 = 88.12 : x
2. Step 2: Convert to fraction form
   89.80/123.54 = 88.12/x
3. Step 3: Cross multiply
   89.80x = 123.54 × 88.12
4. Step 4: Simplify right side
   89.80x = 10,886.34
5. Step 5: Solve for x
   x = 10,886.34/89.80
6. Step 6: Final answer
   x = 121.23