———————————Assignment 4

title: “R Notebook” output: html_notebook

Exploring the CO2 Dataset Ken Wood (2024) In this assignment basic statistical analysis techniques is applied using the R programming language on the CO2 dataset.

Load the package

library(gtsummary)
library (dplyr)

## 
## Attaching package: 'dplyr'

## The following objects are masked from 'package:stats':
## 
##     filter, lag

## The following objects are masked from 'package:base':
## 
##     intersect, setdiff, setequal, union

library(dataset)
library(ggplot2)

#Import the CO2 dataset

head(CO2)

##   Plant   Type  Treatment conc uptake
## 1   Qn1 Quebec nonchilled   95   16.0
## 2   Qn1 Quebec nonchilled  175   30.4
## 3   Qn1 Quebec nonchilled  250   34.8
## 4   Qn1 Quebec nonchilled  350   37.2
## 5   Qn1 Quebec nonchilled  500   35.3
## 6   Qn1 Quebec nonchilled  675   39.2

A set of summary stats for the dataset

summary(CO2)

##      Plant             Type         Treatment       conc          uptake     
##  Qn1    : 7   Quebec     :42   nonchilled:42   Min.   :  95   Min.   : 7.70  
##  Qn2    : 7   Mississippi:42   chilled   :42   1st Qu.: 175   1st Qu.:17.90  
##  Qn3    : 7                                    Median : 350   Median :28.30  
##  Qc1    : 7                                    Mean   : 435   Mean   :27.21  
##  Qc3    : 7                                    3rd Qu.: 675   3rd Qu.:37.12  
##  Qc2    : 7                                    Max.   :1000   Max.   :45.50  
##  (Other):42

Create a histogram of CO2 uptake by grass plant

hist(CO2$uptake, 
     main="Histogram of CO2$uptake",
     xlab="conc Value",
     ylab="Frequency",
     col="blue",
     border="black")

Interpretation: CO₂ concentration ranged from 95 to 1000 ppm, with a median of 350 ppm and a mean of 435 ppm, indicating a slight right skew. The 25th and 75th percentiles were 175 ppm and 675 ppm, respectively. This shows that plants were exposed to a broad gradient of CO₂ levels, from low to very high concentrations.

Create a Boxplot Comparing two samples

ggplot(CO2, aes(x=Type, y=uptake)) + geom_boxplot()

Interpretation: Quebec plants show a higher median CO₂ uptake (~37) with more consistent values, although a few low outliers are present. In contrast, Mississippi plants have a lower median uptake (~20) and greater variability, but without extreme outliers. Overall, Quebec plants absorb more CO₂ than Mississippi plants.