1) You turn your web browser to the online Harris Interactive Poll. Based on 2234 responses, the poll reports that 45% of U.S. adults believe that global climate change exists and humans are the main cause, 30% believe global climate change exists but that its causes are mainly not related to humans, 13% do not believe global climate change exists and 12% are undecided. A researcher computed a 95% confidence interval for the proportion of all U.S. adults who do not believe in global climate change to be from 12% to 14%. Interpret this result.
(A) Anywhere from 12% to 14% of all U.S. adults do not believe in global climate change.
(B) The computed interval can't be trusted since it was computed from a voluntary response sample.
(C) We are 95% confident that 13% of all U.S. adults do not believe in global climate change give or take 1%.
(D) Given the data, there is a 95% probability that the true proportion of U.S. adults that do not believe in global climate change is between 12% and 14%.
(E) We are 95% confident that the sample of 2234 U.S. adults that do not believe in global climate change is between 12% and 14%.
2. A test of significance is based on computing a number that compares the value of the parameter stated by the null hypothesis with an estimate of the parameter from the sample data. In general, what is this number called?
(A) The null hypothesis
(B) The critical value
(C) The P-value
(D) The sample mean x ¯
(E) The test statistic
3. A probability that is computed, for a statistical test, by using a probability distribution that models the chance, if H0 is true, that a test statistic would take a value at least as extreme as that actually observed from sample data is called what?
(A) The significance level (↵)
(B) The P-value (D)
(C) The population mean (μ)
(D) The probability of "success" on each trial.
(E) A two-sided test
4. There has been recent evidence to suggest that American adults weigh more, on average, than they did a quarter of a century ago. A biostatistician at the Quillen College of Medicine is curious whether the mean weight (μ) of all college students has increased, as well. Suppose that the mean weight of college students was 150 pounds in 1980. The researcher plans to examine the weights of a random sample of college students in 2017 to see if the mean weight of all college students has increased significantly in 37 years. What is the appropriate null hypothesis for the test?
(A) H0 :μ=150
(B) H0 :μ±150
(C) H0 :μ>150
(D) H0 :μ6=150
(E) H0 :μ<150