Question 3 Load trees dataset in R/Rstudio by running the line data("trees"). This data set provides measurements of the diameter, height and volume of timber in 31 felled black cherry trees.

Note that the diameter (in inches) is erroneously labelled Girth in the data. It is measured at 4 ft 6 in above the ground. 1. Display first 6 lines of the data set. 2. Display some numerical summary for each of the variables in the dataset. 3. Compute how many trees in the data have heights which are greater than 80. 4. Construct a relative histogram of the height variable and comment on your observations. 5. Assume each height follows a Normal distribution. Compute by hand a 90% confidence interval for the true mean height. You can use R to compute the summary statistics and multipliers you need to construct the Cl. 6. At 10% level of significance, test whether the mean height is smaller than 73. Use R to obtain the test results. Clearly show your work for the 4-steps of hypothesis testing.