Finding the Fourth Proportional to 78.31, 117.47 and 42.27

Step by Step Solution

1. Step 1: Write the proportion equation
   78.31 : 117.47 = 42.27 : x
2. Step 2: Convert to fraction form
   78.31/117.47 = 42.27/x
3. Step 3: Cross multiply
   78.31x = 117.47 × 42.27
4. Step 4: Simplify right side
   78.31x = 4,965.46
5. Step 5: Solve for x
   x = 4,965.46/78.31
6. Step 6: Final answer
   x = 63.41