Problem 1

LengthCT <- c(75,85,91.6,95,NA,105.5,106)
Tb <- c(0,0,1,NA,0,0,0)

Average lengthCT of animals

mean(LengthCT, na.rm = TRUE)
## [1] 93.01667

Problem 2

Farm <- c(rep("MO",4),"LN","SE","QM")
Month <- c(11,7,7,NA,9,9,11)
Boar <- cbind(Farm,Month,LengthCT,Tb)
dim(Boar)
## [1] 7 4

dim gives the size(rows, columns) of the dataframe: \(7 \times 4\)

nr <- nrow(Boar)
nr
## [1] 7

nrow gives the number of rows in the dataframe: 7

nc <- ncol(Boar)
nc
## [1] 4

ncol gives the number of columns in the dataframe: 4

Problem 3

Year <- c(00,00,01,NA,03,03,02)
Sex <- c(1,2,2,2,1,2,2)
LengthClass <- rep(1,7)
Ecervi <- c(rep(0,3),NA,rep(0,3))
df <- data.frame(Farm,Month,Year,Sex,LengthClass,LengthCT,Ecervi,Tb)
df
##   Farm Month Year Sex LengthClass LengthCT Ecervi Tb
## 1   MO    11    0   1           1     75.0      0  0
## 2   MO     7    0   2           1     85.0      0  0
## 3   MO     7    1   2           1     91.6      0  1
## 4   MO    NA   NA   2           1     95.0     NA NA
## 5   LN     9    3   1           1       NA      0  0
## 6   SE     9    3   2           1    105.5      0  0
## 7   QM    11    2   2           1    106.0      0  0