Question 1:

link <- 'https://raw.githubusercontent.com/st3vejobs/orange/main/Orange.csv'
orange <- read.csv(url(link), na.strings = "")
summary(orange)
##        X             Tree        age         circumference  
##  Min.   : 1.0   Min.   :1   Min.   : 118.0   Min.   : 30.0  
##  1st Qu.: 9.5   1st Qu.:2   1st Qu.: 484.0   1st Qu.: 65.5  
##  Median :18.0   Median :3   Median :1004.0   Median :115.0  
##  Mean   :18.0   Mean   :3   Mean   : 922.1   Mean   :115.9  
##  3rd Qu.:26.5   3rd Qu.:4   3rd Qu.:1372.0   3rd Qu.:161.5  
##  Max.   :35.0   Max.   :5   Max.   :1582.0   Max.   :214.0
meanage <- mean(orange[["age"]])
medage <- median(orange[["age"]])
meanage
## [1] 922.1429
medage
## [1] 1004
meancir <- mean(orange[["circumference"]])
medcir <- median(orange[["circumference"]])
meancir
## [1] 115.8571
medcir
## [1] 115

Question 2

orangethick <- subset(orange, circumference > 125)
orangethick
##     X Tree  age circumference
## 6   6    1 1372           142
## 7   7    1 1582           145
## 11 11    2 1004           156
## 12 12    2 1231           172
## 13 13    2 1372           203
## 14 14    2 1582           203
## 20 20    3 1372           139
## 21 21    3 1582           140
## 25 25    4 1004           167
## 26 26    4 1231           179
## 27 27    4 1372           209
## 28 28    4 1582           214
## 33 33    5 1231           142
## 34 34    5 1372           174
## 35 35    5 1582           177

Question 3

names(orangethick)[names(orangethick) == "age"] <- "age_days"
names(orangethick)[names(orangethick) == "circumference"] <- "circumference_cm"

orangethick
##     X Tree age_days circumference_cm
## 6   6    1     1372              142
## 7   7    1     1582              145
## 11 11    2     1004              156
## 12 12    2     1231              172
## 13 13    2     1372              203
## 14 14    2     1582              203
## 20 20    3     1372              139
## 21 21    3     1582              140
## 25 25    4     1004              167
## 26 26    4     1231              179
## 27 27    4     1372              209
## 28 28    4     1582              214
## 33 33    5     1231              142
## 34 34    5     1372              174
## 35 35    5     1582              177

Question 4

summary(orangethick)
##        X             Tree          age_days    circumference_cm
##  Min.   : 6.0   Min.   :1.000   Min.   :1004   Min.   :139.0   
##  1st Qu.:12.5   1st Qu.:2.000   1st Qu.:1231   1st Qu.:143.5   
##  Median :21.0   Median :3.000   Median :1372   Median :172.0   
##  Mean   :20.8   Mean   :3.133   Mean   :1365   Mean   :170.8   
##  3rd Qu.:27.5   3rd Qu.:4.000   3rd Qu.:1582   3rd Qu.:191.0   
##  Max.   :35.0   Max.   :5.000   Max.   :1582   Max.   :214.0
meanage2 <- mean(orangethick[["age_days"]])
medage2 <- median(orangethick[["age_days"]])
meanage2
## [1] 1364.733
medage2
## [1] 1372
meancir2 <- mean(orangethick[["circumference_cm"]])
medcir2 <- median(orangethick[["circumference_cm"]])
meancir2
## [1] 170.8
medcir2
## [1] 172
paste0("Comparison: ", cat("\n"),
                  "mean age: ", format(round(meanage, 4), nsmall=1),
                  " thicker age: ", format(round(meanage2, 4), nsmall=1),
                  " median age: ", format(round(medage, 4), nsmall=1),
                  " thicker age: ", format(round(medage2, 4), nsmall=1))
## [1] "Comparison: mean age: 922.1429 thicker age: 1364.733 median age: 1004.0 thicker age: 1372.0"
paste0("Comparison: ", cat("\n"),
                  "mean circumference: ", format(round(meancir, 4), nsmall=1),
                  " thicker circumference: ", format(round(meancir2, 4), nsmall=1),
                  " median circumference: ", format(round(medcir, 4), nsmall=1),
                  " thicker circumference: ", format(round(medcir2, 4), nsmall=1))
## [1] "Comparison: mean circumference: 115.8571 thicker circumference: 170.8 median circumference: 115.0 thicker circumference: 172.0"

Question 5

orangethick$age_days[orangethick$age_days > 1300] <- "old"
orangethick
##     X Tree age_days circumference_cm
## 6   6    1      old              142
## 7   7    1      old              145
## 11 11    2     1004              156
## 12 12    2     1231              172
## 13 13    2      old              203
## 14 14    2      old              203
## 20 20    3      old              139
## 21 21    3      old              140
## 25 25    4     1004              167
## 26 26    4     1231              179
## 27 27    4      old              209
## 28 28    4      old              214
## 33 33    5     1231              142
## 34 34    5      old              174
## 35 35    5      old              177