Programming Assignment 1: Quiz >> R Programming

Programming Assignment 1: Quiz >> R Programming

1. What value is returned by the following call to pollutantmean()? You should round your output to 3 digits.

pollutantmean("specdata", "sulfate", 1:10)

• 4.064
• 3.666
• 6.026
• 3.782
• 6.545
• 4.868

2. What value is returned by the following call to pollutantmean()? You should round your output to 3 digits.

pollutantmean("specdata", "nitrate", 70:72)

• 2.752
• 2.394
• 0.914
• 1.182
• 1.706
• 2.604

3. What value is returned by the following call to pollutantmean()? You should round your output to 3 digits.

pollutantmean("specdata", "sulfate", 34)

• 0.680
• 1.477
• 0.450
• 1.300
• 1.573
• 0.591

4. What value is returned by the following call to pollutantmean()? You should round your output to 3 digits.

pollutantmean("specdata", "nitrate")

• 1.703
• 2.493
• 2.363
• 2.233
• 1.842
• 1.774

5. What value is printed at end of the following code?

cc <- complete("specdata", c(6, 10, 20, 34, 100, 200, 310))
 print(cc$nobs)

• 204 222 200 212 213 198 196
• 215 201 188 204 193 213 206
• 217 210 206 214 211 203 211
• 228 148 124 165 104 460 232
• 201 214 235 183 198 210 210
• 227 184 189 196 232 224 189

6. What value is printed at end of the following code?

cc <- complete("specdata", 54)
 print(cc$nobs)

• 219
• 248
• 213
• 205
• 220
• 228

7. What value is printed at end of the following code?

RNGversion("3.5.1")  
 set.seed(42)
 cc <- complete("specdata", 332:1)
 use <- sample(332, 10)
 print(cc[use, "nobs"])

• 608 885 684 510 765 171 244 745 624 216
• 270 310 27 692 307 681 631 455 690 440
• 643 99 703 673 59 366 277 644 318 594
• 524 577 276 487 3 592 5 148 645 435
• 711 135 74 445 178 73 49 0 687 237

8. What value is printed at end of the following code?

cr <- corr("specdata")                
 cr <- sort(cr)   
 RNGversion("3.5.1")
 set.seed(868)                
 out <- round(cr[sample(length(cr), 5)], 4)
 print(out) 

• -0.0203 0.5856 0.0983 0.3840 0.1137
• -0.0351 0.2736 -0.0176 0.5520 0.1828
• 0.2688 0.1127 -0.0085 0.4586 0.0447
• 0.1539 -0.0056 0.3023 0.4158 0.2558
• 0.4474 0.4720 0.1239 0.5220 0.2538
• 0.3792 0.5118 0.3620 0.4726 0.5782

9. What value is printed at end of the following code?

cr <- corr("specdata", 129)                
 cr <- sort(cr)                
 n <- length(cr)    
 RNGversion("3.5.1")
 set.seed(197)                
 out <- c(n, round(cr[sample(n, 5)], 4))
 print(out)

• 243.0000 0.2540 0.0504 -0.1462 -0.1680 0.5969
• 225.0000 0.4216 0.4207 -0.0507 0.9377 0.0277
• 229.0000 -0.2418 0.4496 0.8748 -0.3924 -0.5713
• 233.0000 -0.6377 0.3773 -0.0759 0.7335 0.2879
• 247.0000 0.1958 0.9304 -0.4851 -0.8229 -0.0679
• 242.0000 0.8233 0.3443 -0.2242 -0.7703 0.8735

10. What value is printed at end of the following code?

cr <- corr("specdata", 2000)                
 n <- length(cr)                
 cr <- corr("specdata", 1000)                
 cr <- sort(cr)
 print(c(n, round(cr, 4)))

• 0.0000 -0.8974 0.8278 0.4519
• 3.0000 0.5342 -0.6713 0.3684
• 2.0000 0.5596 -0.5655 -0.1241
• 3.0000 -0.0206 -0.5881 0.5135
• 0.0000 -0.0190 0.0419 0.1901
• 3.0000 -0.8907 0.4755 -0.0175