Year	x	Price in $ per Million Btu
1990		6.31
1991		6.14
1992		6.32
1993		6.75
1994		6.8
1995		6.34
1996		7.46
1997		8.12
1998		8.04
1999		8.25
2000		9.58
2001		11.28
2002		9.25

The following table shows data for the cost of natural gas in Maryland (in dollars per Million Btu) for x years since 1990.

1. Define the explanatory and response variables for this problem.

2. Use the calculator to obtain the linear regression line of best fit for the original prices; round to three decimal places. Write this prediction equation in the form:

3. In a brief sentence, interpret the slope in the context of the problem.

4. Predict the price in dollars per million Btu for the year 2010. Then calculate the residual for the year 2010 if the actual price in 2010 was $11.57 per million Btu.

5. What is the correlation coefficient, rounded to two decimal places. Is the linear association between the variables weak or strong? How do you know?

6. Conduct an outlier test as defined by the OUTLIER FORMULA and indicate any low or high outliers. (Show all work)

6.31

6.14

6.32

6.75

6.8

6.34

7.46

8.12

8.04

8.25

9.58

11.28

9.25