Hi I have some uni problems in my exam revision i can't sort out.
215mg of nicotine in a standard cigarette
a) find the probability a single cigarette has a nicotine content more than 220mg
b) if a random sample of 25 cigarettes is selected, what is the probability that the mean is more than 220mg
I tried using Z=y-u/sd but the z score from the table was 0.629 which can be correct right?
PLEASE help i dont know what model i should be using!!
Also, i have no idea about part b! HELP!