Question

hey simple random sample of 25 filtered 100 in in cigarettes is at 10 and the tar content of each cigarette is measured the sample has a mean of 19.2 MG in a standard deviation of 3.29 MG you say 0.05 significance level to test the claim that the mean tar content of filtered hundred MM cigarettes is less than 21.1 MG which is the main for unfiltered king-size cigarettes assume that the simple random sample has been selected for my normally distributed population

Answer 1

Here claim is that mean is less than 21.1

So hypothesis is vs

As sample size is less than 30, but distribution is normal so we will use t statistics

The t-critical value for a left-tailed test, for a significance level of α=0.05 is

tc​=−1.711

Graphically

As t statistics falls in the rejection region we reject the null hypothesis

Hence we have sufficient evidence to support the claim that mean is less than 21.1