Given below are Microsoft Excel outputs for various estimated autoregressive (AR) models for Australia's greenhouse gas - CO2 emissions (metric tons per capita) from 2000 to 2020. From the data, you also know that the real CO2 emissions (metric tons per capita) in Australia for 2018, 2019 and 2020 are 15.49, 15.24 and 15.22, respectively.

AR(1) Model:

	Coefficients	Standard Error	t Stat	P-value
Intercept	-0.739254405	1.058826038	-0.69818	0.49352
Yi-1	1.03633313	0.061498926	16.85124	0.00000

AR(2) Model:

	Coefficients	Standard Error	t Stat	P-value
Intercept	-0.195598275	1.195728319	-0.16358	0.8719
Yi-1	1.254042159	0.230101005	5.449964	0.0000
Yi-2	-0.247748864	0.252306745	-0.98194	0.3391

AR(3) Model:

	Coefficients	Standard Error	t Stat	P-value
Intercept	0.267661461	1.27502274	0.209927	0.83622
Yi-1	1.193189828	0.237113007	5.032157	0.000102
Yi-2	-0.006585142	0.343435519	-0.01917	0.984925
Yi-3	-0.206841239	0.200271827	-1.0328	0.316166

1. Using a 5% level of significance, what is the appropriate autoregressive model (AR model) for the CO2 emissions (metric tons per capita) in Australia? Explain your reasoning.
2. If you decide to use the second-order autoregressive model (AR(2) Model), what will the predicted Australia's CO2 emissions (metric tons per capita) be in 2020? Show your calculations.