There is the first attachment with 3 questions

and then the other attachment is with one question.

so four questions in total. And this is due at 11:59 please.

and thank you

If a = .05 for a left-tailed hypothesis test using the 2 test, the critical value is: Question 3 2 pts Benzene is a toxic chemical used in the manufacturing of medicinal chemicals, dyes, articial leather, and linoleum. A manufacturer claims that its exit water meets the federal regulation with a mean of less than 7980 ppm of benzene. To assess the benzene content of the exit water, 10 independent water samples were collected and found to have an average of 7,965 ppm of benzene. Assume a known standard deviation of 78 ppm. Give the test value used for the Hypothesis test that would test the manufacturers claim. Question 4 2 pts A civil engineer is analyzing the compressive strength of concrete. Compressive strength is approximately normally distributed with population variance 1,026.76 psiz. A random sample of 12 specimens has a mean compressive strength of 3,247.39 psi. Give the test value for the hypothesis that the mean compressive strength is greater than 3250 psi. In hypothesis testing about population mean u, if the test statistic falls in the critical region, then the null hypothesis has been proven to be true. 0 True O False