Question

y	x	xy	xx	yy
11.4	0	0	0	129.96
11.9	1	11.9	1	141.61
7.1	2	14.2	4	50.41
14.2	3	42.6	9	201.64
5.9	4	23.6	16	34.81
6.1	5	30.5	25	37.21
5.4	6	32.4	36	29.16
3.1	7	21.7	49	9.61
5.7	8	45.6	64	32.49
4.4	9	39.6	81	19.36
4	10	40	100	16
2.8	11	30.8	121	7.84
2.6	12	31.2	144	6.76
2.4	13	31.2	169	5.76
5.2	14	72.8	196	27.04
2	15	30	225	4
94.2	120	498.1	1240	753.66

a. Use the Equation to estimate Y if X = 3.5                                   Y Estimate = ___________

b. What is the Correlation Coefficient and what does the value tell you about the correlation between X and Y?

c. What is the Coefficient of Determination and what does the value tell you about the correlation between X and Y?

d. Based on your graph, does the data appear to be linear? – give comments to support your answer.

Answer 1

Regression Equation: y = -0.6129x + 10.485

Insert a scatterplot and select any data point and right click --> add trend line. Seelt linear as a trend and also selet "Display an equation on chart" and display R-squared"

a. Use the Equation to estimate Y if X = 3.5  

y = -0.6129x + 10.485

x = 3.5

y = -0.6129*35 + 10.485

y = -10.97

The estimation of predicted value of x = 3.5 is -10.97

b. What is the Correlation Coefficient and what does the value tell you about the correlation between X and Y?

r = -0.80 (Negative correlation)

c. What is the Coefficient of Determination and what does the value tell you about the correlation between X and Y?

Coefficient of Determination is nothing but R-squared

R-square value is alreeady there in the scatter plot snap shot

R-squared = 0.64

d. Based on your graph, does the data appear to be linear? – give comments to support your answer.

Yes the data appear to be negative linear between x and y variable.