Please use RStudio and explain each step

$1.$ In the following you are going to analyze the "Caschool $($The California Test Score$)"$ dataset that comes with the R package Ecdat. In order to access the data set you first need to install the package Ecdat. Once you install the package and load it$,$ the "Caschool" dataset will be available to you and you can load the data set using the data function.

$($a$)$ Briefly describe what the dataset is about, including the variable descriptions.

$(1)$ Use ggplot$2$ to show a histogram of the variable expnstu. Does the histogram look like a normal distribution? Use the Shapiro$-$Wilk test to test for normality and interpret the p$-$value.

$($o$)$ Use ggplot$2$ to plot the scatter plot of the variables mathscr and readscr and interpret the results.

$($q$)$ Use ggplot$2$ to plot a heatmap of the variables avginc and expnstu employing the rainbow colors and interpret the results.