library(dplyr)
mtcars |>
filter(mpg > 20) |>
select(mpg, wt, hp) |>
mutate(ratio = mpg / wt) mpg wt hp ratio
Mazda RX4 21.0 2.620 110 8.015267
Mazda RX4 Wag 21.0 2.875 110 7.304348
Datsun 710 22.8 2.320 93 9.827586
Hornet 4 Drive 21.4 3.215 110 6.656299
Merc 240D 24.4 3.190 62 7.648903
Merc 230 22.8 3.150 95 7.238095
Fiat 128 32.4 2.200 66 14.727273
Honda Civic 30.4 1.615 52 18.823529
Toyota Corolla 33.9 1.835 65 18.474114
Toyota Corona 21.5 2.465 97 8.722110
Fiat X1-9 27.3 1.935 66 14.108527
Porsche 914-2 26.0 2.140 91 12.149533
Lotus Europa 30.4 1.513 113 20.092531
Volvo 142E 21.4 2.780 109 7.697842






