Need help with regression statistics analysis

#1
Hello I need serious help. I did my last project fine. I've followed all my instructions for this final project, and did everything, but the part to interpreting my regression on analysis makes no sense. I have a set of act scores and Grade point average scores, and turned it into a regression table. I've done that. Now the teacher told me to interpret the results, how to do this wasn't brought to me well in class. I'm really supposed to interpret this for scores for african americans and their gpa and act scores. I can post the act scores if you need. Thanks and God Bless.

Regression Statistics
Multiple R 0.88358236
R Square 0.780717786
Adjusted R Square 0.763849924
Standard Error 0.194760814
Observations 15

The rest(ANOVA data) is to long, and hard to format to put on this forum, so maybe I can e-mail the rest to someone? Thanks and God Bless.
 
E

elnaz

Guest
#5
Hello
Please , post me table of score and ANOVA data(in word or spss, splus, minitab) .
 
#6
Here are the results.

Okay thanks a lot. Sorry if this is long, I can e-mail it in excel or word if you need it.

As mentioned I have to interpet my results for african americans and their gpa and act scores.

A university was interested in finding out how well ACT scores predicted the first-semester GPA of freshman. Data for 15 freshman are presented below.

ACT Scores GPA
24 3.25
21 2.87
18 2.66
22 3.33
22 2.87
22 3.21
18 2.76
28 3.91
29 3.55
18 2.55
20 2.44
24 3.22
25 3.22
24 3.44
21 3.01

Okay here are the statistics. The Regression stats are above.

Anova (this is the anova table)
df SS MS F Signiicance F
Regression 1 1.755646929 1.755647 46.28433 1.25624E-05
Residual 13 0.493113071 0.037932
Total 14 2.24876

Coefficients Standard error t-stat p-value Lower 95%
Intercept 0.72177665 0.3511329 2.055565 0.060486 -0.03679986
ACT Scores 0.10554569 0.015513989 6.803259 1.26E-05 0.07202975

(this is the rest of the above table)
Upper 95% Lower 90.0% Upper 90.0%
1.48035316 0.09994368 1.34360962
0.13906162 0.07807144 0.13301993

Sorry if this is to long, I have to interpret this based on the GPA scores. I have done the table and regression analysis in excel already, just have no idea how to interpret this. Thanks and God Bless.
 
#7
Hmm, I don';t know why the results turned out like that, thats not the way I formatted it, maybe I can send it in excel or word. It won't post right, let me try something else.
 
E

elnaz

Guest
#8
Hello
You take notice whereas in Anova table sig is very smaller than .01 then refuse H0,
Then to calculate R =SS(reg)/SS(T) that is very small ,you can view
p-value for b0 , in consequence of act score dont have any effect on GPA.
 
#10
Hmmm okay so you don't need me to re-post it in a better format do you? Or I can e-mail the data. By anyways, okay so looking at the data ACT scores have no impact on the GPA score, because in the anova table the significance is smaller than .01 and when I calculate R=SS. So after all of that I will be able to have my interpretation? Thanks and God Bless
 

JohnM

TS Contributor
#11
If you plot ACT scores vs GPA, there is a positive correlation between them - as ACT scores increase, GPA tends to increase.
 
#12
Okay so it's a possitive correlation, I add that to my interpretation anova table interpetation? I'm trying to figure out how to word my interpretation of the data.
 

JohnM

TS Contributor
#14
This is a bit more involved than what can be covered in a post - not really complicated, but you could write a decent length paper on how to interpret regressions and the associated ANOVA table.

You should check out the Online Statistics Resources post in our Examples section. Vassar College's online stats textbook is highly recommended.

Also, a very good book that is easy to read and does a thorough job of explaining regression and the associated outputs (SPSS and/or Excel) is: Regression Basics
 
#16
Okay I have everything so far. But on the data I set my confidence interval at 90% so looking at the ANOVA table how will I be able to tell is there was a statistical significance between ACT Scores and GPA scores. Will I be able to find out if the Significance is lower or high? I see enlav said .01, but I wanted to make sure that was right. Also my Significance F is "1.25624E-05" Thanks and God Bless.
 
#17
Any ideas on my last question of how to find statistical significance with a 90% interval, like what is the formula for determing significance with significance F, my last question. Thanks and God Bless
 
#19
ALso, since the signficance F is smaller than .01 that means the ACT and GPA scores are statistically significant right? It seems as my significant F is larger than .01, which makes it not significant.
 
#20
Hey John or anybody else, ignore my other questions. I turned my paper in, and the teacher says I didn't do a regression line graph, how do I do this in microsoft excel, and do I get the regression line data from the ACT and GPA scores or from the ANOVA table? Need it by tommorrow. Thanks and God Bless.