Suppose an ophthalmologist reviews mdus photographs of 30 patients with maoular degeneration both before and 3 months after receiving a laser treatment. To assess the efficacy,F of treatment, each patient is rated as improved, remained the same, or declined. If 20 patients improved, 7 declined, and 3 remained the same, then assess whether or not patients undergoing this treatment are showing signicant change from baseline to 3 months afterward. Report a p value. Use a sign test