1. The EPA wants to test randomly selected sample of n water specimens and test the mean daily rate of pollution produced by a mining operation. If the EPA wants a 95% level of confidence and a sampling error of 1 mg/L, how many water specimens are required in sampling? Assume pollution readings in water samples are approximately normal with a standard deviation of 5 mg/L.
A.97
B.10
C.a sample of greater than 30
D.None of the above
2. A random sample of 500 immigrants participated in a study about the ethnic background and the level of education of immigrants. Using 1% level of significance and p-value of 0%, test the claim that ethnic background of immigrants is independent of their level of education
A.Yes, they are independent.
B.No, they are not independent.
C.We cannot answer the question with the available information.
3. For a set of paired data, the variable used to predict the other variable is called
A.the dependent variable (y)
B.the independent variable (X)
C.the non-determination variable
D.the determination variable
E.none of the above
4. A medical researcher contends that lung capacity varies significantly between smokers and nonsmokers. The mean capacity of a sample of 30 nonsmokers is 5.0 litters with a sample standard deviation of 0.3 liters. At the 0.01 significance level, is there sufficient evidence to conclude that lung capacity is larger among nonsmokers, if lung capacity of smokers is 4.0 litters?
A.Yes
B.No
C.We cannot answer the question with the available information.