In: Statistics and Probability
Question 2:
In this part, we will use t-procedures. t-procedures are both confidence intervals and hypothesis tests that
use a t distribution. They are called t-procedures because they rely on a t-test statistic and/or a t-critical
value, so we only need to know the results of a sample in order to perform these procedures for a population
You will use the data file TempSample00-18.
(THIS is Temp sample data)
YEAR,Month,High Temperature
2000,Jan,45
2000,Jan,48
2001,Jan,49
2003,Jan,62
2003,Jan,53
2004,Jan,42
2004,Jan,47
2005,Jan,40
2005,Jan,47
2006,Jan,48
2006,Jan,47
2007,Jan,51
2007,Jan,34
2007,Jan,47
2009,Jan,50
2011,Jan,35
2012,Jan,44
2013,Jan,38
2013,Jan,53
2013,Jan,42
2014,Jan,58
2014,Jan,47
2014,Jan,44
2015,Jan,52
2016,Jan,44
2017,Jan,49
2018,Jan,54
2000,Feb,48
2001,Feb,47
2004,Feb,47
2007,Feb,51
2008,Feb,51
2008,Feb,55
2011,Feb,45
2014,Feb,37
2014,Feb,54
2014,Feb,58
2015,Feb,54
2017,Feb,52
2017,Feb,44
2017,Feb,45
This includes an SRS of daily temperature highs from January and February from the years 2000-2018
(i.e. “recent” highs). The distribution of “recent” daily high temperatures is approximately Normal.
A.
1) Describe the intended population?
2) Describe the sample?
3) Describe the variable of interest?
4) Describe the parameter of interest (in context)?
5) Describe the statistic of interest (in context)? Give a numerical value along with your description.
Round to two decimal places.
B.
1) Check that the conditions for using t-procedures are satisfied. If they are not, discuss whether or not it is reasonable to use t-procedures.
C.
1) What degrees of freedom are needed?
2) What critical value is used to compute a 95% confidence interval?
3) Give the 95% confidence interval. Round to two decimal places.
4) Interpret your 95% confidence interval.
D.
1) Perform a hypothesis test for α = .01. Be sure to interpret your p-value in context.
E.
1) Based on your work in Part B, what would you say about the daily high temperature for “recent” years compared to “historical” years?