Finding the Fourth Proportional to 91.72, 137.59 and 42.96

Step by Step Solution

1. Step 1: Write the proportion equation
   91.72 : 137.59 = 42.96 : x
2. Step 2: Convert to fraction form
   91.72/137.59 = 42.96/x
3. Step 3: Cross multiply
   91.72x = 137.59 × 42.96
4. Step 4: Simplify right side
   91.72x = 5,910.76
5. Step 5: Solve for x
   x = 5,910.76/91.72
6. Step 6: Final answer
   x = 64.45