Part B$-$Performing an ANOVA in $R-$Effect of ventilation on blood folate levels

Several studies have been published to show that nitrous oxide used in anesthetics can reduce patient

blood folate levels. This dataset gives measured levels of folate in red blood cells in patients who

received three different methods of ventilation while under anesthesia. The first column in the dataframe,

ventilation, is a categorical variable $($or "factor"$)$ containing one of the three ventilation methods for

each patient:

The second column in the dataframe, is a numerical variable, folate, which is the folate concentration

$(\frac{g}{l})$ for each patient. $[$This dataset is from the "ISwR" library of datasets available in the ISwR package

at

www$.$r$-$project.org.$]$

Procedure

First, change the directory in $R($under the File menu$)$ to wherever you saved the "red$\_$cell" file.

Then read in this data set using the load$()$ command in $R.$ Type the following command:

load$("$red$\_$cell.RData"$)$

Alternatively, you can have $R$ open a file browser window as follows:

load$($file$.$choose $())$

Once you've read in the data set, you can access the two data vectors in this data frame using the $"$ $ $"$

command $($i$.$e$.$ red$\_$cell$ventilation and red$\_$cell$folate$)$ or you can make the

individual data vectors available using the command:

attach $($red$\_$cell$)$

After this command you can access the data vectors just as ventilation and folate

$4.$ Make boxplots and stripcharts of this dataset using the following commands:

boxplot$($folate ventilation$)$

stripchart$($folate ventilation$)$

$[$paste a copy of your boxplot here$]$

$[$paste a copy of your stripchart here$]$