Face masks used by firefighters often fail by having their l

Face masks used by firefighters often fail by having their lenses fall out when exposed to very high temperatures. A manufacturer of face masks claims that for their masks the average temperature at which pop out occurs is 550

Solution

mu =550

n =75

sample mean x bar = 470

a) Population of interest here are fire personnel who work under high temperature with lens

b) All face masks in the population are fire service men

c) Sample are the people selected