For Exercises 7–9, do the following, for the indicated data:

  1. Find the point estimate of , for the given .
  2. Calculate and interpret a 95% confidence interval for the mean value of for the given .
  3. Compute and interpret a 95% prediction interval for a randomly chosen value of for the given .

Question 13.153

9. Data in Exercise 3, for a used car that is eight years old

13.99.9

(a) 6.818 thousand dollars (b) (5.805, 7.831). We are 95% confident that the mean price for 8-year-old cars of this make and model lies between 5.805 thousand dollars and 7.831 thousand dollars (c) (4.902, 8.733). We are 95% confident that the price for a randomly selected 8-year-old car of this make and model lies between 4.902 thousand dollars and 8.733 thousand dollars.