Finding the Fourth Proportional to 78.23, 117.27 and 42.18

Step by Step Solution

1. Step 1: Write the proportion equation
   78.23 : 117.27 = 42.18 : x
2. Step 2: Convert to fraction form
   78.23/117.27 = 42.18/x
3. Step 3: Cross multiply
   78.23x = 117.27 × 42.18
4. Step 4: Simplify right side
   78.23x = 4,946.45
5. Step 5: Solve for x
   x = 4,946.45/78.23
6. Step 6: Final answer
   x = 63.23