3. The following table shows the average temperature outside compared to the cost of electricity for a certain house for 7 months. Average Temperature Electricity Bill
99 $150
94 $124
87 $101
84 $98
75 $82
72 $85
69 $80

(a) Using the hottest and coolest months data, find the line of best fit for this data showing all steps by hand. SHOW WORK.

(b) Using your equation from part (a), determine the average monthly temperature rounded to the nearest tenth if the electricity bill totaled $112. SHOW WORK.

(c) Using your equation from part (a), determine the electricity bill total if the average monthly temperature was 87 degrees. SHOW WORK

(d) Find the correlation coefficient of the data and use this value to describe the strength and direction of the association. Is there causation?