Using the SATGPA data set in Stat2Data package. Test by using α=.05.
1) Create the following three variables and then print out allthe six variables.
Create a new variable “SATâ€, which is the sum of MathSAT andVerbalSAT.
Create second new variable “SATLevelâ€, and assign the value of“SATLevel†as 1 when
SAT<=1100, 2 when1100SAT>1300.
Create third new variable “GPALevel†and assign the value of“GPALevel†as 1 when
GPA<=2.8, 2 when2.83.5
Print out all the data in the descending order of their GPALeveland the ascending order of
their SAT when GPALevel is thesame.
2) Use the Chi-Square test to conclude if the SATLevel andGPALevel are independent.
3) Compute the mean and variance of “GPA†for each level of“GPALevelâ€, and compute the
correlation matrices for the four variables: MathSAT, VerbalSAT,GPA and SAT.
4) Do the data provide sufficient evidence to indicate that themean of MathSAT is significantly greater
than the mean of VerbalSAT.
5) Test if the proportion of MathSAT greater than VerbalSAT is0.6.
