HW3-RBasics-Pratt.Rmd

data(AirPassengers)
AirPassengers

##      Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
## 1949 112 118 132 129 121 135 148 148 136 119 104 118
## 1950 115 126 141 135 125 149 170 170 158 133 114 140
## 1951 145 150 178 163 172 178 199 199 184 162 146 166
## 1952 171 180 193 181 183 218 230 242 209 191 172 194
## 1953 196 196 236 235 229 243 264 272 237 211 180 201
## 1954 204 188 235 227 234 264 302 293 259 229 203 229
## 1955 242 233 267 269 270 315 364 347 312 274 237 278
## 1956 284 277 317 313 318 374 413 405 355 306 271 306
## 1957 315 301 356 348 355 422 465 467 404 347 305 336
## 1958 340 318 362 348 363 435 491 505 404 359 310 337
## 1959 360 342 406 396 420 472 548 559 463 407 362 405
## 1960 417 391 419 461 472 535 622 606 508 461 390 432

mean(AirPassengers)

## [1] 280.2986

median(AirPassengers)

## [1] 265.5

summary(AirPassengers)

##    Min. 1st Qu.  Median    Mean 3rd Qu.    Max. 
##   104.0   180.0   265.5   280.3   360.5   622.0

January1950=(AirPassengers[13])
January1960=(AirPassengers[133])
January1950+January1960

## [1] 532

January1960-January1950

## [1] 302

Yr1950=(AirPassengers[13:24])
Yr1950[2]

## [1] 126

5. The length of the 1950 AirPassengers data sequence is 12 terms long.

sum(Yr1950)

## [1] 1676

data(mtcars)
View(mtcars)

carmtx=matrix(data=c(mtcars$cyl,mtcars$disp,mtcars$hp), ncol=3)
carmtx=carmtx[order(carmtx[,1]),]
carmtx

##       [,1]  [,2] [,3]
##  [1,]    4 108.0   93
##  [2,]    4 146.7   62
##  [3,]    4 140.8   95
##  [4,]    4  78.7   66
##  [5,]    4  75.7   52
##  [6,]    4  71.1   65
##  [7,]    4 120.1   97
##  [8,]    4  79.0   66
##  [9,]    4 120.3   91
## [10,]    4  95.1  113
## [11,]    4 121.0  109
## [12,]    6 160.0  110
## [13,]    6 160.0  110
## [14,]    6 258.0  110
## [15,]    6 225.0  105
## [16,]    6 167.6  123
## [17,]    6 167.6  123
## [18,]    6 145.0  175
## [19,]    8 360.0  175
## [20,]    8 360.0  245
## [21,]    8 275.8  180
## [22,]    8 275.8  180
## [23,]    8 275.8  180
## [24,]    8 472.0  205
## [25,]    8 460.0  215
## [26,]    8 440.0  230
## [27,]    8 318.0  150
## [28,]    8 304.0  150
## [29,]    8 350.0  245
## [30,]    8 400.0  175
## [31,]    8 351.0  264
## [32,]    8 301.0  335

carmtx2=matrix(data=c(carmtx[1:11,2],carmtx[1:11,3]), ncol=2)
carmtx2

##        [,1] [,2]
##  [1,] 108.0   93
##  [2,] 146.7   62
##  [3,] 140.8   95
##  [4,]  78.7   66
##  [5,]  75.7   52
##  [6,]  71.1   65
##  [7,] 120.1   97
##  [8,]  79.0   66
##  [9,] 120.3   91
## [10,]  95.1  113
## [11,] 121.0  109

mean(carmtx2[,1])

## [1] 105.1364

mean(carmtx2[,2])

## [1] 82.63636