Finding the Fourth Proportional to 53.91, 80.84 and 42.47

Step by Step Solution

1. Step 1: Write the proportion equation
   53.91 : 80.84 = 42.47 : x
2. Step 2: Convert to fraction form
   53.91/80.84 = 42.47/x
3. Step 3: Cross multiply
   53.91x = 80.84 × 42.47
4. Step 4: Simplify right side
   53.91x = 3,433.27
5. Step 5: Solve for x
   x = 3,433.27/53.91
6. Step 6: Final answer
   x = 63.69