Finding the Fourth Proportional to 89.57, 123.57 and 71.12

Step by Step Solution

1. Step 1: Write the proportion equation
   89.57 : 123.57 = 71.12 : x
2. Step 2: Convert to fraction form
   89.57/123.57 = 71.12/x
3. Step 3: Cross multiply
   89.57x = 123.57 × 71.12
4. Step 4: Simplify right side
   89.57x = 8,788.61
5. Step 5: Solve for x
   x = 8,788.61/89.57
6. Step 6: Final answer
   x = 98.12