You can use the following syntax to check your answers. Note the answers you get in R will not be EXACTLY the same you get by hand but they should be pretty close.

If you sample standard deviation s = 2 and the sample size = 35, and your confidence level is 95% this is how you can have R calculate a Confidence Interval for \(\sigma\).

conf_sig(s = 2, size = 35, conf = .95)
## [1] 1.617744 2.620404

9.3

5. (10.117,30.144).

7. (9.542,40.289).

9. Type answer here.

  1. (7.94,23.66).
  2. (8.586,20,635).
  3. (6,615,31.364).

11. .(226, .495).

13. 734.78,1656.74.