R question

A

i$.$ Download the dataset called "Crop dataset" from the course Moodle page in the

block for "Spring Term Week $7".$ The name of the file should be "crop.csv$".$

ii$.$ Move the dataset into a subdirectory on your computer with a name that is

something like "Homework for Week $7$ Spring". You can choose the exact name.

The path to the dataset on my computer is:

C:IMy Documents$|$teaching$|$Statistics $2022|$Seminars$|$Week $7$ Spring

iii. Create a project in the subdirectory where you have placed your dataset.

iv$.$ Open a new R Script and use the read.csv$()$ command to open the file "crop.csv$"$

which you will call "crop$\_$dataset" and view the data using the View$()$ command.

v$.$ Compute the mean crop yield when fertilizer equals $1$ and the mean crop yield

when fertilizer equals $3.$

vi$.$ Perform a t test of the hypothesis that the mean crop yield when fertilizer is set to

$"1"$ is equal to the mean crop yield when fertilizer is set to $"3"$ against the alternative

hypothesis that the mean crop yield when fertilizer is set to $"1"$ is less than the mean

crop yield when fertilizer is set to $"3".$

vii. Create a new $($fake$)$ variable called "pollution" by using the command sample$().$

It must have $96$ elements with each element being a random draw from the vector:

$(1,2,3,4,5)$

Of course, your vector does not actually measure levels of pollution but, for the

purpose of this question we will pretend that it does.

viii. Modify your dataframe "crop$\_$dataset" by adding a third variable: "pollution".

ix$.$ Compute the median pollution level when fertilizer is equal to $2.$