Make a plot to show the number of Covid-19 infections over time in the United states (4-12 March 2020)

# Make a plot to show the number of Covid-19 infections over time
# in the U.S. (nine days of records: 4-12 March 2020)
# Source: https://covidtracking.com/

Infected <- c(118, 176, 223, 341, 417, 584, 778, 1050, 1308)

Day <- 1:(length(Infected))  # length is the number of observation days
N <- 327200000  # population of U.S.

Plot these data

# If you use a PC, remove the # sign in the next line and add # to following line
# windows(height=5, width=5)
quartz.options(height=5, width=5)
plot.new()
par(oma = c(0.1,1.0,0.1,0.1))
plot(Day, Infected, las = 1, pch=19, col="blue", cex=1.2)
title("Confirmed Cases of Covid-19 in the U.S.")