7. Cigarette Smoking A re

arette Smoking A researcher found that a cigarette

Joker smokes on average 31 cigarettes a day. She

feels that this average is too high. She selected a random

sample of 10 smokers and found that the mean number

of cigarettes they smoked per day was 28. The sample

standard deviation was 2.7. At a= 0.05 is there enough

evidence to support her claim?