Finding the Fourth Proportional to 89.72, 134.72 and 83.91

Step by Step Solution

1. Step 1: Write the proportion equation
   89.72 : 134.72 = 83.91 : x
2. Step 2: Convert to fraction form
   89.72/134.72 = 83.91/x
3. Step 3: Cross multiply
   89.72x = 134.72 × 83.91
4. Step 4: Simplify right side
   89.72x = 11,303.94
5. Step 5: Solve for x
   x = 11,303.94/89.72
6. Step 6: Final answer
   x = 126.00