The composition of the air in an artificial environment is controlled by a computer chip which makes decisions based upon information received from sensors in the chamber. Comp A 27.6 27.9 26.3 28.5 27.9 25.4
Comp B 27.9 28 27.1 28.1 28 26.9
Tests are made with sensors purchased from companies A and B. The following data represent recorded percentages of oxygen taken in pairs according to the number of people in the chamber:
Use the sign test to determine whether the median percentages are different at the 5% significance level.