Finding the Fourth Proportional to 78.91, 118.17 and 38.20

Step by Step Solution

1. Step 1: Write the proportion equation
   78.91 : 118.17 = 38.20 : x
2. Step 2: Convert to fraction form
   78.91/118.17 = 38.20/x
3. Step 3: Cross multiply
   78.91x = 118.17 × 38.20
4. Step 4: Simplify right side
   78.91x = 4,513.50
5. Step 5: Solve for x
   x = 4,513.50/78.91
6. Step 6: Final answer
   x = 57.20