1.Eighteen undergraduate students were randomly selected from a university and their systolic blood pressure was tested. The sample mean and standard deviation were 126.4 mmHg and 11.0 mmHg respectively. What is the obtained t-score for this sample under the null hypothesis Ho:= 118?

2.To compare the treatment effect of two medications, two independent samples of patient performance data were collected. The sample sizes are 15 and 18 respectively. Assuming that the two populations shared the same variance, the researchers decided to conduct a two independent samples test for the means. They found that the difference between the two sample means was4.0 and the pooled sample standard deviation of the two samples was 4.2. What would be the obtainedt-value under the null hypothesis that assumes no difference between the two population means?

3.We selected a random sample of size200 from a pool of university students and asked whether they use Facebook on a regular basis.Eighty replied yes. What would be your estimation of the standard error of the sample proportion of regular Facebook users based upon the given information?