Hide hint for Question 11 The variable in column C is called an indicator variable. 1 is recorded when air is good and 0 is recorded when bad. The sum total is the number of times air quality was good. The number of rows of data is the sample size. The mean of the air quality indicator variable is the relative frequency of good air and also the sample proportion for this problem. Compute the mean of the Air Quality data (column C) for the sample proportion. "test the hypothesis that proportion of times that air quality meets standards is at least 90%" translates to test H0: Proportion 0.90. HA: Proportion < 0.90. This is a one-tailed test with lower rejection region. Week 8 Presentation, slide 8 Week 8 Presentation- Examples, tab Proportion The rejection rule is, "when the pvalue is low (pvalue < alpha) H0 must go" and we state that the evidence against H0 is Extreme when p value < 0.001 Overwhelming when 0.001 p value < 0.01 Strong when 0.01 p value < 0.05 Weak when 0.05 p value < 0.10 Insignificant when 0.10 p value