Utilizando o dataset flights do pacote nycflights13 ou então no link:\ https://raw.githubusercontent.com/ismayc/pnwflights14/master/data/flights.csv responda as questões que seguem:

library(nycflights13)
data(flights)
head(flights)
tail(flights)
  1. Faça uma breve descrição deste conjunto de dados;
library(tidyverse)
## -- Attaching packages ------------------------------------------- tidyverse 1.2.1 --
## v ggplot2 3.2.1     v purrr   0.3.2
## v tibble  2.1.3     v dplyr   0.8.3
## v tidyr   1.0.0     v stringr 1.4.0
## v readr   1.3.1     v forcats 0.4.0
## -- Conflicts ---------------------------------------------- tidyverse_conflicts() --
## x dplyr::filter() masks stats::filter()
## x dplyr::lag()    masks stats::lag()
summary(flights)
##       year          month             day           dep_time   
##  Min.   :2013   Min.   : 1.000   Min.   : 1.00   Min.   :   1  
##  1st Qu.:2013   1st Qu.: 4.000   1st Qu.: 8.00   1st Qu.: 907  
##  Median :2013   Median : 7.000   Median :16.00   Median :1401  
##  Mean   :2013   Mean   : 6.549   Mean   :15.71   Mean   :1349  
##  3rd Qu.:2013   3rd Qu.:10.000   3rd Qu.:23.00   3rd Qu.:1744  
##  Max.   :2013   Max.   :12.000   Max.   :31.00   Max.   :2400  
##                                                  NA's   :8255  
##  sched_dep_time   dep_delay          arr_time    sched_arr_time
##  Min.   : 106   Min.   : -43.00   Min.   :   1   Min.   :   1  
##  1st Qu.: 906   1st Qu.:  -5.00   1st Qu.:1104   1st Qu.:1124  
##  Median :1359   Median :  -2.00   Median :1535   Median :1556  
##  Mean   :1344   Mean   :  12.64   Mean   :1502   Mean   :1536  
##  3rd Qu.:1729   3rd Qu.:  11.00   3rd Qu.:1940   3rd Qu.:1945  
##  Max.   :2359   Max.   :1301.00   Max.   :2400   Max.   :2359  
##                 NA's   :8255      NA's   :8713                 
##    arr_delay          carrier              flight       tailnum         
##  Min.   : -86.000   Length:336776      Min.   :   1   Length:336776     
##  1st Qu.: -17.000   Class :character   1st Qu.: 553   Class :character  
##  Median :  -5.000   Mode  :character   Median :1496   Mode  :character  
##  Mean   :   6.895                      Mean   :1972                     
##  3rd Qu.:  14.000                      3rd Qu.:3465                     
##  Max.   :1272.000                      Max.   :8500                     
##  NA's   :9430                                                           
##     origin              dest              air_time        distance   
##  Length:336776      Length:336776      Min.   : 20.0   Min.   :  17  
##  Class :character   Class :character   1st Qu.: 82.0   1st Qu.: 502  
##  Mode  :character   Mode  :character   Median :129.0   Median : 872  
##                                        Mean   :150.7   Mean   :1040  
##                                        3rd Qu.:192.0   3rd Qu.:1389  
##                                        Max.   :695.0   Max.   :4983  
##                                        NA's   :9430                  
##       hour           minute        time_hour                  
##  Min.   : 1.00   Min.   : 0.00   Min.   :2013-01-01 05:00:00  
##  1st Qu.: 9.00   1st Qu.: 8.00   1st Qu.:2013-04-04 13:00:00  
##  Median :13.00   Median :29.00   Median :2013-07-03 10:00:00  
##  Mean   :13.18   Mean   :26.23   Mean   :2013-07-03 05:22:54  
##  3rd Qu.:17.00   3rd Qu.:44.00   3rd Qu.:2013-10-01 07:00:00  
##  Max.   :23.00   Max.   :59.00   Max.   :2013-12-31 23:00:00  
## 
glimpse(flights)
## Observations: 336,776
## Variables: 19
## $ year           <int> 2013, 2013, 2013, 2013, 2013, 2013, 2013, 2013,...
## $ month          <int> 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,...
## $ day            <int> 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,...
## $ dep_time       <int> 517, 533, 542, 544, 554, 554, 555, 557, 557, 55...
## $ sched_dep_time <int> 515, 529, 540, 545, 600, 558, 600, 600, 600, 60...
## $ dep_delay      <dbl> 2, 4, 2, -1, -6, -4, -5, -3, -3, -2, -2, -2, -2...
## $ arr_time       <int> 830, 850, 923, 1004, 812, 740, 913, 709, 838, 7...
## $ sched_arr_time <int> 819, 830, 850, 1022, 837, 728, 854, 723, 846, 7...
## $ arr_delay      <dbl> 11, 20, 33, -18, -25, 12, 19, -14, -8, 8, -2, -...
## $ carrier        <chr> "UA", "UA", "AA", "B6", "DL", "UA", "B6", "EV",...
## $ flight         <int> 1545, 1714, 1141, 725, 461, 1696, 507, 5708, 79...
## $ tailnum        <chr> "N14228", "N24211", "N619AA", "N804JB", "N668DN...
## $ origin         <chr> "EWR", "LGA", "JFK", "JFK", "LGA", "EWR", "EWR"...
## $ dest           <chr> "IAH", "IAH", "MIA", "BQN", "ATL", "ORD", "FLL"...
## $ air_time       <dbl> 227, 227, 160, 183, 116, 150, 158, 53, 140, 138...
## $ distance       <dbl> 1400, 1416, 1089, 1576, 762, 719, 1065, 229, 94...
## $ hour           <dbl> 5, 5, 5, 5, 6, 5, 6, 6, 6, 6, 6, 6, 6, 6, 6, 5,...
## $ minute         <dbl> 15, 29, 40, 45, 0, 58, 0, 0, 0, 0, 0, 0, 0, 0, ...
## $ time_hour      <dttm> 2013-01-01 05:00:00, 2013-01-01 05:00:00, 2013...

Tem-se 336776 observações referentes a 19 variáveis que caracterizam uma empresa aérea no ano de 2013, considerando a data de partida, horários reais de partida e chegada, horários de partida e chegada programados, atrasos de partida e chegada, origem e destino, quantidade de tempo gasto no ar (em minutos), Distância entre aeroportos (em milhas), etc.

  1. Encontre os voos que foram para Houston (IAH ou HOU);
dados <- as_tibble(flights) 
dados
library(dplyr)

Houston<-filter(dados,dest == "IAH" | dest == "HOU");Houston
dim(Houston)
## [1] 9313   19
  1. Encontre os voos que foram operados pela United American ou Delta;
UA_DL<-filter(dados,carrier == "UA" | carrier == "DL");UA_DL
dim(UA_DL)
## [1] 106775     19
  1. Encontre os voos que tiveram um atraso de duas ou mais horas na chegada;
Atraso<-filter(dados,arr_delay == "2013" | arr_delay > 120);Atraso
dim(Atraso)
## [1] 10034    19
  1. Encontre os voos que partiram em julho, agosto e setembro.
voo_789<-filter(dados,month == "7" | month == "8" | month == "9");voo_789
dim(voo_789)
## [1] 86326    19
voo_<-filter(dados,month >6 & month < 10);voo_
dim(voo_)
## [1] 86326    19