Psoriasis is a skin disorder with no known cure and no proven effective pharmacological treatment. An alternative treatment for psoriasis is ichthyotherapy, also known as therapy with the "Doctorfish of Kangal." Fish from the hot pools of Kangal, Turkey, feed on the skin scales of bathers, reportedly reducing the symptoms of psoriasis. In one study, 67 patients diagnosed with psoriasis underwent 3 weeks of ichthyotherapy (Evidence-Based Research in Complementary and Alternative Medicine, Dec. 2006). The Psoriasis Area Severity Index (PASI) of each patient was measured both before and after treatment. (The lower the PASI score, the better is the skin condition.) Box plots of the PASI scores, both before (baseline) and after 3 weeks of ichthyotherapy treatment, are shown in the accompanying diagram.

a. Find the approximate 25th percentile, the median, and the 75th percentile for the PASI scores before treatment.
b. Find the approximate 25th percentile, the median, and the 75th percentile for the PASI scores after treatment.
c. Comment on the effectiveness of ichthyotherapy in treating psoriasis.

Transcribed Image Text:

50 40 30 Bascline After 3 weeks