Finding the Fourth Proportional to 91.81, 137.72 and 43.06

Step by Step Solution

1. Step 1: Write the proportion equation
   91.81 : 137.72 = 43.06 : x
2. Step 2: Convert to fraction form
   91.81/137.72 = 43.06/x
3. Step 3: Cross multiply
   91.81x = 137.72 × 43.06
4. Step 4: Simplify right side
   91.81x = 5,930.22
5. Step 5: Solve for x
   x = 5,930.22/91.81
6. Step 6: Final answer
   x = 64.59