Question

The file “EX10-38TUIT.csv” contains the undergraduate tuition in 2008 and 2014 for 33 public universities. Use R to carry out the analysis. a) (2 points) Plot the data with the 2008 tuition on the x axis and describe the relationship. Are there any outliers or unusual values? Does a linear relationship between the tuition in 2008 and 2014 seem reasonable? b) (2 points) Run the simple linear regression and give the least-squares regression line. c) (1 point) Obtain the residuals and plot them versus the 2008 tuition statement. Is there anything unusual in the plot? d) (2 points) The five California schools appear to follow the same linear trend as the other schools, but have higher-than-predicited in-state tuition in 2014. Assume that this jump is particular to this state and remove these five cases and refit the model. How do the parameter estimates change? Question 6 (7 points total) Refer to the previous exercise. We’ll now move forward with inference using the model with the five California schools removed from the dataset. a) (1 point) Give the null and alternative hypotheses for examining whether there is a linear relationship between 2008 and 2014 tuition amounts. b) (2 points) Write down the test statistic and p-value for the hypotheses stated in part a. State your conclusions. c) (2 points) Construct a 95% confidence interval for the slope. What does this interval tell you about the annual percent increase in tuition between 2008 and 2014? d) (1 point) What percent of the variability in 2014 tuition is explained by a linear regression model using the 2008 tuition? e) (1 point) Explain why inference on β0 is not of interest for this problem. Question 7 (3 points total, 1 point each) Refer to the previous two exercises, again making inference using the model with the five California schools removed from the dataset. a) (1 point) Suppose the tuition at Skinflint U was $8,800 in 2008. What is the predicted tuition in 2014? b) (1 point) Suppose the tuition at I.O.U. was $15,700 in 2008. What is the predicted tuition in 2014? 2 c) (1 point) Discuss the appropriateness of using the fitted equation to predict tuition for each of these universities.

Answer 1

As per HomeworkLib rule , i will answer separate question only(question 6) .

please send the reaming question separately , i will answer it .

thank you!