A fast-food place has been touting its half-pound burger, with 8 ounces of ground beef. Because of differences in cooking, its website does mention that there is a standard deviation of 0.5 ounces....

A fast-food place has been touting its half-pound burger, with 8 ounces of ground beef. Because of differences in cooking, its website does mention that there is a standard deviation of 0.5 ounces. How little could the burger weigh before you think that someone should be suspicious of the 'half-pound' claim? Or, how many underweight burgers in a row do you think it would take receiving before someone should be suspicious of that claim?