Consider the following model of the is curve without an international sector: consumption: latex: \frac{c_t}{\bar{y}_t} = \bar{a}_c - \bar{b}_c (r_t - \bar{r}) c t y ¯ t = a ¯ c − b ¯ c ( r t − r ¯ ); investment: latex: \frac{i_t}{\bar{y}_t} = \bar{a}_i - \bar{b}_i (r_t - \bar{r})i t y ¯ t = a ¯ i − b ¯ i ( r t − r ¯ ); and government expenditure: latex: g_t = \bar{a}_g \bar{y}_tg t = a ¯ g y ¯ t. note that latex: \bar{b}_cb ¯ c can be a positive or negative real number. with this formulation, the is curve is: group of answer choices