Biological Statistics: Analysis of Body and Brain Weights of 28 Species of Land Animals

Running head: BIOLOGICAL STATISTICS 1
Biological Statistics
[Name of Student]
[Institutional Affiliation]

BIOLOGICAL STATISTICS 2
Using the R program version 3.5.1
Download the data ‘Animals’ from the ‘MASS’ package. This data is special. The first column
identifies the animals involved in the study. This column is not a variable in the traditional sense.
It is a column of labels.
R codes for downloading the data “Animals” from the ‘MASS’
> library(MASS)
> data(Animals)
1. What is the dimension of the data? (2points)
The Animals data frame has 3 columns and 28 rows. The three columns are;
i. Land anima
ii. Body weight (in kilograms)
iii. Brain weight (in grams)
The data frame is presented as follows (From R console window)
> class(Animals)
[1] "data.frame"
> sapply(Animals,class)
body brain
"numeric" "numeric"
>
2. Describe the data.
The data contains average body and brain weights for 28 species of land animals. The body
weights are recorded in kilograms while the brain weights are recorded in grams.
Summary of the data from the R console window is presented as follows;
> library(MASS)
> data(Animals)
> summary(Animals)
body brain
Min. : 0.02 Min. : 0.40

BIOLOGICAL STATISTICS 3
1st Qu.: 3.10 1st Qu.: 22.23
Median : 53.83 Median : 137.00
Mean : 4278.44 Mean : 574.52
3rd Qu.: 479.00 3rd Qu.: 420.00
Max. :87000.00 Max. :5712.00
> dim(Animals)
[1] 28 2
> summary(Animals$body)
Min. 1st Qu. Median Mean 3rd Qu. Max.
0.02 3.10 53.83 4278.44 479.00 87000.00
> summary(Animals$brain)
Min. 1st Qu. Median Mean 3rd Qu. Max.
0.40 22.23 137.00 574.52 420.00 5712.00
>
3. Show the top ten rows of the data. (2 Points)
R command;
>Animals[1:10, ]
Top ten rows of the data
body brain
Mountain beaver 1.35 8.1
Cow 465.00 423.0
Grey wolf 36.33 119.5
Goat 27.66 115.0
Guinea pig 1.04 5.5
Dipliodocus 11700.00 50.0
Asian elephant 2547.00 4603.0
Donkey 187.10 419.0

BIOLOGICAL STATISTICS 4
Horse 521.00 655.0
Potar monkey 10.00 115.0
4. Show the scatter plot of the data with x-axis ‘body’ and y-axis ‘brain.’ Identify as many
data points as you can. Comment on the plot. (4 points)
Fig 1. Scatter plot of the data (body Vs brain).
Comment;
Based on the scatter plot above, most of the data shows an uphill patter however there are some
outliers in the data. It can therefore be suggested that there exist a positive relationship between
the brain weight and the body weight. Looking at the graph. It is awful. No connection! Most of
the data is sitting in one corner. There seems to be some outliers in the data. From the data set