Finding the Fourth Proportional to 42.91, 64.24 and 28.48

Step by Step Solution

1. Step 1: Write the proportion equation
   42.91 : 64.24 = 28.48 : x
2. Step 2: Convert to fraction form
   42.91/64.24 = 28.48/x
3. Step 3: Cross multiply
   42.91x = 64.24 × 28.48
4. Step 4: Simplify right side
   42.91x = 1,829.32
5. Step 5: Solve for x
   x = 1,829.32/42.91
6. Step 6: Final answer
   x = 42.63