Explore dataset Sales by loading the CSV file available on Blackboard using the read.csv$()$ command into R$/$RStudio$.$

$($a$)$ Use R to calculate the $90\%$ confidence interval for the mean price.

$($b$)$ Is there a relationship between price and sales?

$($i$)$ Write down the equation of the proposed model in your report.

$($ii$)$ Fit an OLS model using $R$ to quantify the relationship between the two variables.

$($iii$)$ What is the coefficient of determination of this model?

$($c$)$ Plot the residuals obtained from your model vs the variable price. Comment on any patterns.

Please write the r code