Answer
Average: $2.43$
Worst case: $3$
Work Step by Step
For finding $1$ in the list: $3$ comparisons
For finding $2$ in the list: $2$ comparisons
For finding $3$ in the list: $3$ comparisons
For finding $4$ in the list: $1$ comparisons
For finding $5$ in the list: $3$ comparisons
For finding $6$ in the list: $2$ comparisons
For finding $7$ in the list: $3$ comparisons
Average :
$\frac{3+2+3+1+3+2+3}{7}=\frac{17}{7}\approx 2.43$
The average, $2.43$, is slightly lower than the worst case which is $3$.
