Finding the Fourth Proportional to 78.72, 117.98 and 35.39

Step by Step Solution

1. Step 1: Write the proportion equation
   78.72 : 117.98 = 35.39 : x
2. Step 2: Convert to fraction form
   78.72/117.98 = 35.39/x
3. Step 3: Cross multiply
   78.72x = 117.98 × 35.39
4. Step 4: Simplify right side
   78.72x = 4,175.43
5. Step 5: Solve for x
   x = 4,175.43/78.72
6. Step 6: Final answer
   x = 53.04