Finding the Fourth Proportional to 91.98, 127.76 and 89.42

Step by Step Solution

1. Step 1: Write the proportion equation
   91.98 : 127.76 = 89.42 : x
2. Step 2: Convert to fraction form
   91.98/127.76 = 89.42/x
3. Step 3: Cross multiply
   91.98x = 127.76 × 89.42
4. Step 4: Simplify right side
   91.98x = 11,424.30
5. Step 5: Solve for x
   x = 11,424.30/91.98
6. Step 6: Final answer
   x = 124.20