1. (2 points) Write down the estimated population regression line.

1. (3 points) Please answer the following questions regarding the slope.

1. Interpret the value of the slopebof the sample regression line in the context of the problem.
2. Show how you would construct the 95% confidence interval for the population slope ?.You may leave the numerical expressions without evaluating or interpreting.
3. (3 points) The temperature on October 11, 2004 was 20 C, and the actual NOxconcentration on that day was 294.00 ppm.Find the predicted NOxconcentration for that day using the estimated population regression line in question 1, and calculate the residual.

1. (2 points) State the value ofr2, and interpret it in the context of the problem.

1. (3 points) Find the correlationrbetween temperature and NOxconcentration, and state the strength and direction of the linear association between these variables.

1. (2 points) Besides the random sample assumption, the linear regression model requires three additional assumptions.Use plots A?C at the bottom of the problem description to determine if these assumptions are satisfied.You only need to assessONEassumption for complete credit.Please specify which assumption your check and which plot (A, B, or C) you use.

1. (5 points) Use the R output to test whether ? = 0 at the 0.05 level, where ? is the slope of the population regression line between temperature and NOxconcentration.Show all five steps.

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