Question 2 (12 marks) In R, load a data set called iris using the following code: data(iris). The data set includes measurement for 150 iris flowers. a) Using the iris data set, find the following confidence intervals (6 marks): i. 90% confidence interval for the true mean of Sepal.Length (using the complete dataset) b) c) d) 90% confidence interval for the true mean of Sepal.Length for observations that come from species setosa. Note that to choose the relevant observations, you need to add code Species=="setosa\" when you use the subset() function. 90% confidence interval for the true mean of Sepal.Length for observations that come from the versicolor species. Indicate what method of calculation you chose for each interval and why (e.g., did you use the z or t distribution). (2 marks) Discuss the findings. Explain what your results show you. (2 marks) Provide the R code that you used to get your results (starting from the line to load the data). (2 marks)