Question

Question 21 3 pts Large Sample Proportion Problem. A survey was conducted on high school marijuana use. Of the 2266 high school students surveyed, 970 admitted to smoking marijuana at least once. A study done 10 years earlier estimated that 45% of the students had tried marijuana. We want to conduct a hypothesis test to see if the true proportion of high school students who tried marijuana is now less than 45%. Use alpha = .01. What is the critical value for this test? 0 -2.576 -2.33 2.33 -1.96

Answer 1

22)

H0: p >= 0.45 24)

Ha: p < 0.45

This is left tailed test.

At 0.01 level,

Critical value = -2.33

23)

Since 0.50 contained in confidence interval, do not reject H0.

I would fail to reject the null hypothesis that p = 0.5

24)

Sample proportion $\hat{p}$ = 470 / 1000 = 0.47

Standard error = sqrt [ $\hat{p}$ ( 1 - $\hat{p}$ ) / n)

= sqrt ( 0.47 * 0.53 / 1000)