Finding the Fourth Proportional to 91.28, 136.81 and 42.47

Step by Step Solution

1. Step 1: Write the proportion equation
   91.28 : 136.81 = 42.47 : x
2. Step 2: Convert to fraction form
   91.28/136.81 = 42.47/x
3. Step 3: Cross multiply
   91.28x = 136.81 × 42.47
4. Step 4: Simplify right side
   91.28x = 5,809.42
5. Step 5: Solve for x
   x = 5,809.42/91.28
6. Step 6: Final answer
   x = 63.64