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. (I don’t really know how to write these on R, so bear with me, please) the .95 one is 10.117, and the .05 one is 30.144

7. the .99 one is 9.542, and the .01 one is 40.289

9.

  1. lower: 7.94, upper: 23.66
  2. lower: 8.59, upper: 20.63
  3. lower: 6.61, upper: 31.36

11. lower: .226, upper: .542 and we are 95% sure that it will fall between .226 and 31.36

13. lower: 734.8, upper: 1657.5 and we are 90% sure that it will fall between 734.8 and 1657.5