Data were collected from a sample of World Campus STAT 200 students during the S
ID: 2908745 • Letter: D
Question
Data were collected from a sample of World Campus STAT 200 students during the Spring 2018 semester. The instructor wants to know if there is evidence of a relationship between students’ scores on the midterm practice quiz and the midterm exam in the population of all World Campus STAT 200 students. All assumptions were met for using linear regression techniques. The following output was obtained from Minitab Express for a simple linear regression model using midterm practice quiz scores to predict midterm exam scores.
A. In this model, what is the explanatory variable and what is the response variable? Explain how you determined this.
B. Identify and interpret the coefficient of determination.
C. Using this output, determine the correlation (Pearson’s r) between midterm practice quiz scores and midterm exam scores.
D. Are midterm practice quiz scores a statistically significant predictor of midterm exam scores? Explain how you determined this.
E. If a student has a midterm practice quiz score of 14, what is this student’s predicted midterm exam score?
F. A student has a midterm practice quiz score of 14 and a midterm exam score of 55. Compute this student’s residual.
G. Interpret the residual that you computed in part F.
H. Is it valid to use this regression model to predict the midterm exam scores of students in STAT 200 at Penn State York this semester? Explain why or why not.
Explanation / Answer
A) From the given scatter plot, Explanatory variable is scores in Mid term practice Quiz
and Response variable is Scores in Mid term Exam.
since Exaplanatory variable is always taken in the X axis
and Response variable is in Y axis.
B) Given that
Coeffiecient of determination(R2) = 0.3149
It Interprets There is oly 31.49% of variation explained between scores of Midterm practice quiz and Midterm Exam.
C) Correlation Coefficient (r) = sqrt(0.3149) = 0.5612
D) Yes, Mid term practice quiz scores are statistically significant, since p value = 0.001 < 0.05
or p value is very small.
Hence scores are statistically significant.
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.