In 2011,computers of Brand a Controlled 25% of the Market,Brand

Essay

In 2011,computers of Brand A controlled 25% of the market,Brand B 20%,Brand C 10%,and brand D 45%.In 2015,sample data was collected from many randomly selected stores throughout the country.Of the 1,200 computers sold,280 were Brand A,270 were Brand B,90 were Brand C,and 560 were Brand D.Has the market changed since 2011? Test at the 1% significance level.