Extract the daily COVID-19 confirmed cases for City1, City2, and City3 from all the cities. Normalize the daily COVID-19 confirmed cases for the three cities using their respective populations. The 2019 mid-year estimated population figures for City1, City2, and City3 are 100,000, 200,000, and 300,000 respectively.

df <- read.csv ("coronavirus.csv", header = TRUE ) library(dplyr) df %>% group_by(City.name) %>% summarise(Sum = sum(Daily.cases))

Cant select multiple variables from dplyr::Groupby. Can anyone help me with the right code along with the second part of the question as I am not able to find solution as well.