5.14 Reducing high blood pressure by diet requires reduction of sodium intake, which usually requires switching from processed foods to their natural counterparts. Listed below are the average sodium contents of five ordinary foods in processed form and natural form for equivalent quantities. Find a confidence-interval estimate of the median difference

(processed minus natural) with confidence coefficient at least 0.87 using two different procedures.

Natural Food Processed Food Corn of the cob 2 Canned corn 251 Chicken 63 Fried chicken 1220 Ground Sirloin 60 All-beef frankfurter 461 Beans 3 Canned beans 300 Fresh tuna 40 Canned tuna 409