Given:
[tex]\text{Temperatures are }12^{\circ},-2^{\circ},-6^{\circ},8.4^{\circ}[/tex][tex]\text{Average}=\frac{Sum\text{ of the terms}}{No\text{ of the terms}}[/tex][tex]\text{Average}=\frac{12-2-6+8.4}{4}[/tex][tex]\text{Average}=\frac{12.4}{4}[/tex][tex]\text{Average}=3.1[/tex][tex]\text{Therefore, Average temperature in Alaska at 9am is 3.1}^{\circ}[/tex]
