Question

QUESTION 1:

The University of Chicago's General Social Survey (GSS) is the nation’s most important social science sample survey. The GSS asked a random sample of adults their opinion about whether astrology is very scientific, sort of scientific, or not at all scientific. Here is a two-way table of counts for people in the sample who had three levels of higher education degrees:

	Degree Held
	Junior College	Bachelor	Graduate
Not at all scientific	45	124	71
Very or sort of scientific	30	63	28

Give three 95% confidence intervals, for the percents of people with each degree who think that astrology is not at all scientific.

Degree held	pˆp^ (±±0.0001)	SE (±±0.0001)	95% confidence interval (±±0.0001)
Junior college			to
Bachelor			to
Graduate			to

QUESTION 2:

Sample surveys on sensitive issues can give different results depending on how the question is asked. A University of Wisconsin study divided 2400 respondents into 3 groups at random. All were asked if they had ever used cocaine. One group of 800 was interviewed by phone; 167 said they had used cocaine. Another 800 people were asked the question in a one-on-one personal interview; 195 said "Yes." The remaining 800 were allowed to make an anonymous written response; 223 said "Yes."

Are there statistically significant differences among these proportions?

Carry out a chi-square test for association between education level and opinion about astrology. Test H0:H0: the proportion of people who admit cocaine use is the same for all three interview methods versus Ha:Ha: the proportions are not the same (interview type makes a difference). Use α=0.01α=0.01.

χ2(±0.0001)=χ2(±0.0001)=

P(±0.0001)=P(±0.0001)=

There is evidence that interview type makes a difference

There is no evidence that interview type makes a difference

Answer 1