Question

Question 2. linear Regr ession (5Marks) The following data are the monthly salaries Y and the grade point averages X for students who obtained a bachelor's degree in business administration. GPA X 2.6 3.4 3.6 3.2 3.5 2.9 Salary Y, S3300 S3600 S4000 S3500 S3900 $3600 Answer all the following questions 1) Develop a scatter diagram for these data. (1 mark) 2) Is there any relationship between GPA and Salary? (1 mark) 3) Compute the coefficient of correlation for this data. (1 mark) 4) Comment on the value of the coefficient of correlation.(1 mark) 5) Use the regression equation to predict the monthly salary of a graduate with a GPA equal 3.85 (1 mark)

Note : the answer should be computerized please

Answer 1

Ans:

	GPA(x)	Salary(y)	xy	x^2	y^2
1	2.6	3300	8580	6.76	10890000
2	3.4	3600	12240	11.56	12960000
3	3.6	4000	14400	12.96	16000000
4	3.2	3500	11200	10.24	12250000
5	3.5	3900	13650	12.25	15210000
6	2.9	3600	10440	8.41	12960000
Sum=	19.2	21900	70510	62.18	80270000

Slope,b=(6*70510-19.2*21900)/(6*62.18-19.2^2)=581.08

y-intercept,a=(21900-581.0811*19.2)/6=1790.54

Regression eqn:

y'=581.08x+1790.54

when x=3.85

y'=581.08*3.85+1790.54=4027.70

Cofficient of correlation,r=(6*70510-19.2*21900)/SQRT((6*62.18-19.2^2)*(6*80270000-21900^2))=0.864

There is strong positive correlation between GPA and salary,higher the GPA and higher the salary.

Salary(yi) 4500 y 581.08x 1790.5 3500 2500 1500 1000 500 0.5 1.5 2.5 3.5