Finding the Fourth Proportional to 78.48, 117.75 and 42.48

Step by Step Solution

1. Step 1: Write the proportion equation
   78.48 : 117.75 = 42.48 : x
2. Step 2: Convert to fraction form
   78.48/117.75 = 42.48/x
3. Step 3: Cross multiply
   78.48x = 117.75 × 42.48
4. Step 4: Simplify right side
   78.48x = 5,002.02
5. Step 5: Solve for x
   x = 5,002.02/78.48
6. Step 6: Final answer
   x = 63.74