In the Rancho Bernardo Study (n=3785), the mean diastolic blood pressure was 89.2 with a standard deviation of 17.5. Generate the 95% confidence interval for the true mean DBP.

A subset of the Rancho Bernardo Study of 15 children had a mean diastolic blood pressure of 88.1 with a standard deviation of 17.4. Generate the 95% confidence interval for the true mean DBP.

Using the following data from the Rancho Bernardo Study, generate a 95% confidence interval for the difference in mean SBP between the younger and older participants.

	N	Mean	Std Dev
<45 years old	1851	122.1	17.4
45+ years old	1683	128.9	21.5

In the Rancho Bernardo Study (n=3785),1,213 participants reported a BMI that was overweight or obese. Generate a 95% confidence interval for the true proportion of the study population that was overweight or obese.

A pre-test and post-test were given to 5 participants of a smoking cessation workshop. The pre- and post-test results are listed in the table below. Generate the 95% confidence interval for the mean of the difference in scores.

Subject ID	Pre-test	Post-test	Difference	(difference)2
1	14	17
2	13	18
3	15	17
4	17	20
5	12	15

Two different interventions for weight loss were compared in a study. One involved using a food diary and daily weigh-ins and the other involved using a smart phone app to track calories. Construct a 95% confidence interval for the difference in proportions of patients who lost weight during the 6 week study.

Treatment	N	Number who lost weight	Proportion
Food Diary	50	27
Phone App	50	34