Research Scenario

Diastolic blood pressure (DBP) measurements from the general population form a normal distribution with a m = 82 mmHg and s = 10 mmHg.Epidemiological studies have shown that diabetes is a contributing factor to high DBP. Using data from a cohort study, a researcher obtained a sample of n = 144 diabetics whose average DBP was x = 85.Do these data indicate that diabetes is associated with significantly higher DBP in this sample?Test with alpha=.05.

Note

= population mean

x = sample mean

s = standard deviation

What is the null hypothesis in written and mathematical format?