Finding the Fourth Proportional to 90.48, 123.79 and 89.98

Step by Step Solution

1. Step 1: Write the proportion equation
   90.48 : 123.79 = 89.98 : x
2. Step 2: Convert to fraction form
   90.48/123.79 = 89.98/x
3. Step 3: Cross multiply
   90.48x = 123.79 × 89.98
4. Step 4: Simplify right side
   90.48x = 11,138.62
5. Step 5: Solve for x
   x = 11,138.62/90.48
6. Step 6: Final answer
   x = 123.11