Question

A statistics professor would like to build a model relating student scores on the first test to the scores on the second test. The test scores from a random sample of 21 students who have previously taken the course are given in the table. Test Scores First Test Grade Second Test Grade Student 58 73 51 42 La

Answer 1

Sol:

in excel

install analysis tool pak

Then go to

Data >Data analysis>Regression

select Y as second_test_grade

X as First_test_grade

You will get

Book1 - Excel Tell me what you want to do... Adabala Naveenkumarven kat Share Home Insert Page Layout Formulas Data Review View First test grade A1 Sensitivity: Not set Public Internal Confidential Restricted F A C G H K M N O 1 First test Second test grade Regression X 86 58 Input 90 53 Input Y Range SB$1:$B$22 73 62 Cancel 45 79 Input X Range: SAS1SA$22 6 97 48 Help 81 62 Labels Confidence Level Constant is Zero 43 95 Qutout options 10 1: 42 79 O Qutput Range 12 61 65 O New Wurksheet Plva 13 61 72 O New Workbook 74 14 52 Residuals 15 43 76 Residuals Stardardized Residuals Residual Plots Line Fit Plots 16 62 67 17 76 60 18 45 73 Normal Probability Normal Probability Plots 19 73 65 20 73 61 21 48 75 22 92 56 23 24 25 Sheet1 + Ready + 100% 10:46 PM Type here to search S. x 7/8/2019

SUMMARY OUTPUT
Regression Statistics
Multiple R	0.963517
R Square	0.928366
Adjusted R Square	0.924596
Standard Error	2.411903
Observations	21
ANOVA
	df	SS	MS	F	Significance F
Regression	1	1432.424	1432.424	246.2363	2.48E-12
Residual	19	110.5282	5.817275
Total	20	1542.952
	Coefficients	Standard Error	t Stat	P-value	Lower 95%	Upper 95%
Intercept	97.27099	2.023023	48.08199	2.6E-21	93.03675	101.5052
First _test_grade	-0.47019	0.029964	-15.6919	2.48E-12	-0.53291	-0.40748

INTREPRETATION

ANSWER:

yi^=97.271-0.4702*xi