PROBLEM 3 (25 points)
A Rollercoaster's auditors estimate that the average daily loss from those illegally riding without tickets is never more than $200, but wants to determine the accuracy of this statistic. The company researcher takes a random sample of losses over 49 days and finds that = $187 and s = $30.
a) Test at α = 0.05.
b) Construct a 95% confidence interval of losses.
a) Test at α = 0.05. To conduct the test, you need to start by stating the null and alternative hypothesis as follows H0:... View the full answer
- I do not understand where does 2.0106 comes from :(
- Apr 01, 2018 at 5:40pm
- Its obtained from t tables at alpha=0.025 and 48 degrees of freedom of you can use excel formula =T.INV.2T(0.05,48)
- Apr 01, 2018 at 5:50pm
- I found this table: http://www.sjsu.edu/faculty/gerstman/StatPrimer/t-table.pdf but I can't find the value 2.0106, I apologize but I am trying to understand the concept rather than copying, I really appreciate your help :)
- Apr 01, 2018 at 5:56pm
- If you are using t tables the value to use is 2.021. That is where d.f =40 and two tail =0.05, Note that the table assumes that from d.f =40 to 59, value of t will be the same and that's why there is no 48 in the table
- Apr 01, 2018 at 6:02pm
- Do you recommend using these tables or do the calculations in excel?
- Apr 01, 2018 at 6:04pm
- Any will be OK, the difference will be very small to even notice but i recommend excel since the excel values are exact .
- Apr 01, 2018 at 6:10pm
- Thank you so much for your help, I wasn't grasping the concept and I was having a hard time and thus stressing out. I really appreciate your help with this problem :)
- Apr 01, 2018 at 6:16pm