Stats module 5 (A+ Graded 100% Verified)

Stats module 5 (A+ Graded 100% Verified) one tailed test Ans: 1-2a two tailed test Ans: 1-a significance level if type 1 is worse Ans: 1% significance level if type 2 is worse Ans: 10% significance level if both are the same Ans: 5% if p value is less than significance level Ans: reject the null hypothesis If p-value is greater than the significance level Ans: we fail to reject the null hypothesis if you reject the null Ans: there is sufficient evidence if you fail to reject null hypothesis Ans: there is not sufficient evidence type 1 error Ans: rejecting a true null hypothesis type 2 error Ans: failing to reject a false null hypothesis one proportion z-test Ans: - random sample - more than 15 successes and failures Two-proportion z-test Ans: - categorical -independent random sample - more than 10 successes and failures Ho: p1=p2 Ha: p1p2 one mean t test Ans: - random sample - normal population pooled t test Ans: - largest/smallest st. dev is less than 2 - random - independent - normal population non-pooled t test Ans: - largest/smaller st. dev is greater than 2 - approx normal population or large enough sample size to ensure normality - independent random samples paired t test Ans: - population is claimed to be normal - sample size Is at least 30 - looks normal based on qq plot ANOVA test Ans: - random sample - independent - largest/smallest st dev is less than 2 - sample size for each group is normal/above 30 interpreting the CI for the difference in proportions Ans: - if 0 is in the CI, it is plausible that p1=p2 - if 0 is not in the CI, infer that p1 does not equal p2 factor Ans: categorical explanatory variable levels Ans: possible values of the factor if the CI contains 0 Ans: No difference between means if the CI does NOT contain 0 Ans: difference between the means