This lab exercise is due 23:59 Monday 15 March (NZDT).

  • You should submit an R file (i.e. file extension .R) containing R code that assigns values to the appropriate symbols.
  • Your R file will be executed in order and checked against the values that have been assigned to the symbols using an automatic grading system. Marks will be fully deducted for non-identical results.
  • Intermediate steps to achieve the final results will NOT be checked.
  • Each question is worth 0.2 points.
  • You should submit your R file on Canvas.
  • Late assignments are NOT accepted unless prior arrangement for medical/compassionate reasons.

Question 1

Generate the sequence of values from 200 to 400, incremented by 2. Hint: check out the seq() help page with ?seq.

x <- seq(200, 400, by = 2)
x

#>   [1] 200 202 204 206 208 210 212 214 216 218 220 222 224 226 228 230
#>  [17] 232 234 236 238 240 242 244 246 248 250 252 254 256 258 260 262
#>  [33] 264 266 268 270 272 274 276 278 280 282 284 286 288 290 292 294
#>  [49] 296 298 300 302 304 306 308 310 312 314 316 318 320 322 324 326
#>  [65] 328 330 332 334 336 338 340 342 344 346 348 350 352 354 356 358
#>  [81] 360 362 364 366 368 370 372 374 376 378 380 382 384 386 388 390
#>  [97] 392 394 396 398 400

Question 2

Obtain remainders when x is divided by 3. Hint: what is R’s modulus operator?

remainder <- x %% 3
remainder

#>   [1] 2 1 0 2 1 0 2 1 0 2 1 0 2 1 0 2 1 0 2 1 0 2 1 0 2 1 0 2 1 0 2 1
#>  [33] 0 2 1 0 2 1 0 2 1 0 2 1 0 2 1 0 2 1 0 2 1 0 2 1 0 2 1 0 2 1 0 2
#>  [65] 1 0 2 1 0 2 1 0 2 1 0 2 1 0 2 1 0 2 1 0 2 1 0 2 1 0 2 1 0 2 1 0
#>  [97] 2 1 0 2 1

Question 3

Subset x given that the remainders are equal to zero.

x2 <- x[remainder == 0]
x2

#>  [1] 204 210 216 222 228 234 240 246 252 258 264 270 276 282 288 294
#> [17] 300 306 312 318 324 330 336 342 348 354 360 366 372 378 384 390
#> [33] 396

Question 4

Find the number of elements of x2.

n_x2 <- length(x2)
n_x2

#> [1] 33

Question 5

Calculate the 95% range of x2 given by 2 standard deviations of the mean. (DO NOT round your results!)

sd_x2 <- 2 * sd(x2)
mean_x2 <- mean(x)
rng_x <- c(mean_x2 - sd_x2, mean_x2 + sd_x2)
rng_x

#> [1] 183.9655 416.0345