Question

A study investigated ways to prevent staph infections in surgery patients. In a first step, the researchers examined the nasal secretions of a random sample of 6771 patients admitted to various hospitals for surgery. They found that 1251 of these patients tested positive for Staphylococcus aureus, a bacterium responsible for most staph infections.

Let the mean of the sampling distribution be p=0.19.

a) What does p stand for in this case (in words)?

What is the sample in this case?

What is the sample size?

What is the sample proportion p-hat in this case?

b) Use "Rule 1" to show the 68-95-99.9 Rule for this setting:

About 68% of values fall within one standard deviation of the mean.: ______________________

About 95% of the values fall within two standard deviations from the mean:__________________

About 99.7% of the values fall within three standard deviations from the mean:__________________

c) In Exercise 22.1 you found the statistic (p-hat). Find how many standard deviations from the mean p-hat is, by calculating its standard score i.e z=(p-hat - p ) / sqrt (p (1-p) / n

Answer 1