解:$(2)①$当$n = 14$时,因为$n<16,$代入$y = 10n - 80,$得$y = 10×14 - 80=140 - 80 = 60($元$)$
∴当$n = 14$时,该花店这天的利润为$60$元
$②$当$n<16$时,令$70 = 10n - 80,$移项可得$10n=70 + 80,$$10n = 150,$解得$n = 15$
对照表格,日需求量$n = 15$时的天数是$2$天
∴该花店这$10$天中日利润为$70$元的天数是$2$天