In [7]: # Group by campaign id and calculate overall average CPM data_KAG %>% group_by (campaign_id) %>% summarise(campaign_CPM = sum (Spent) /sum(Impress `summarise ()* ungrouping output (override with * groups* argument) campaign id campaign_CPM A tibble: 3 OE 2936 0.3559674 916 0.3100067 1178 0.2717564 2.3 Answer - Q1b The campaign averagely spent the least efficiently on brand awareness(most CPM) cam- paign_id = 936 which has averagely 0.356 CPM 2.3.1