A survey conducted five years ago by the health center at a university showed that 18% of the students smoked at the time. This year a new survey was conducted on a random sample of 200 students from this university, and it was found that 50 of them smoke. We want to find if these data provide convincing evidence to suggest that the percentage of students who smoke has increased over the last five years. What are the test statistic (Z) and p-value of the test

Test statistics = 2.29

P-value = 0.01101

Step-by-step explanation:

We are given that a survey conducted five years ago by the health center at a university showed that 18% of the students smoked at the time. This year a new survey was conducted on a random sample of 200 students from this university, and it was found that 50 of them smoke.

Let Null Hypothesis, : p = 0.18 {means that the percentage of students who smoke has remained same at 18% over the last five years}

Alternate Hypothesis, : p > 0.18 { means that the percentage of students who smoke has increased over the last five years}

The test statistics used here will be ;

       T.S. = ~ N(0,1)

where, = sample proportion of students = 50/200 = 0.25

            n = sample size = 200

So, test statistics =

                            = 2.29

Now, P-value is given by = P(Z > 2.29) = 1 - P(Z <= 2.29)

                                                               = 1 - 0.98899 = 0.01101 or 1.101 %

Therefore, P-value of the test is 0.01101 .

introduction, methodology, results, discussion

step-by-step explanation:

an observational study is one which consists of actual observation to record data and then analyse the data.

there are a number of factors that should be analyzed before starting an observational study.

the main four factors are:

i) introduction:   this should be analysed to check whether the purpose of the study is correctly established and the data recorded are appropriate for the study

methodology:   the method of collecting the data, such as whether randomly selected, and whether sample size matches with the population to be studied, whether questions asked are easy to answer by common men, etc.

results: then results such as summary of data with comments should be studied thoroughly

discussion:   the last is the discussion, this can be either by management people or persons who are all interested , etc.

i got 142 as my answer

step-by-step explanation: