Finding the Fourth Proportional to 89.91, 135.48 and 89.91

Step by Step Solution

1. Step 1: Write the proportion equation
   89.91 : 135.48 = 89.91 : x
2. Step 2: Convert to fraction form
   89.91/135.48 = 89.91/x
3. Step 3: Cross multiply
   89.91x = 135.48 × 89.91
4. Step 4: Simplify right side
   89.91x = 12,181.01
5. Step 5: Solve for x
   x = 12,181.01/89.91
6. Step 6: Final answer
   x = 135.48