Mini Project 25-1

Question 1. What is the median of the first column?

data(cars)
median(cars[,1])

## [1] 15

Dataset for questions 2-4

library(readr)
On_Time_Performance <- read_csv("On_Time_Performance.csv")

## New names:
## • `` -> `...110`

## Warning: One or more parsing issues, call `problems()` on your data frame for details,
## e.g.:
##   dat <- vroom(...)
##   problems(dat)

## Rows: 570131 Columns: 110
## ── Column specification ────────────────────────────────────────────────────────
## Delimiter: ","
## chr  (28): UniqueCarrier, Carrier, TailNum, Origin, OriginCityName, OriginSt...
## dbl  (54): Year, Quarter, Month, DayofMonth, DayOfWeek, AirlineID, FlightNum...
## lgl  (27): Div2WheelsOff, Div2TailNum, Div3Airport, Div3AirportID, Div3Airpo...
## date  (1): FlightDate
## 
## ℹ Use `spec()` to retrieve the full column specification for this data.
## ℹ Specify the column types or set `show_col_types = FALSE` to quiet this message.

Question 3. How many missing values does the column Div2WheelsOff contain?

data <- read.csv("On_Time_Performance.csv")  
sum(is.na(data$Div2WheelsOff))

## [1] 570122

Question 4. What is the average departure delay by carrier? Which carrier shows the largest departure delay?

library(dplyr)

## 
## Attaching package: 'dplyr'

## The following objects are masked from 'package:stats':
## 
##     filter, lag

## The following objects are masked from 'package:base':
## 
##     intersect, setdiff, setequal, union

data <- read.csv("On_Time_Performance.csv")
avg_delays <- data %>%
  group_by(Carrier) %>%
  summarise(Avg_DepDelay = mean(DepDelay, na.rm = TRUE)) %>%
  arrange(desc(Avg_DepDelay))
print(avg_delays)

## # A tibble: 18 × 2
##    Carrier Avg_DepDelay
##    <chr>          <dbl>
##  1 B6             20.4 
##  2 F9             16.0 
##  3 OO             15.1 
##  4 OH             13.8 
##  5 EV             13.6 
##  6 9E             12.4 
##  7 G4             10.4 
##  8 DL              9.74
##  9 YV              8.86
## 10 MQ              8.82
## 11 WN              8.03
## 12 YX              7.26
## 13 AA              6.93
## 14 UA              5.87
## 15 NK              5.61
## 16 VX              2.83
## 17 HA              1.72
## 18 AS             -2.25

largest_delay_carrier <- avg_delays$Carrier[1]
largest_delay_carrier

## [1] "B6"

Question 5. What is the maximum of daily close price for BTC in the data?

library(jsonlite)

## Warning: package 'jsonlite' was built under R version 4.4.3

url <- "https://min-api.cryptocompare.com/data/v2/histoday?fsym=BTC&tsym=USD&limit=100"
response <- fromJSON(url)

btc_data <- response$Data$Data

max_close_price <- max(btc_data$close, na.rm = TRUE)

print(paste("The maximum daily closing price for BTC in the last 100 days is:", max_close_price))

## [1] "The maximum daily closing price for BTC in the last 100 days is: 106155.61"