Question

10. Applicants for a job in a foreign country are given a language proficiency test. The following data shows the number of years they have studied the language and their grade on the test.

No. of years,x	3	4	4	5	3	6	2	3	7
Test grade, y	61	68	75	82	73	90	58	72	93

1. (2 pts.)Plot the scatter diagram for the data on the axes below:

2. (3 pts.)Find the coefficient of correlation ( r

3. (3 pts.)Find the Regression line equation for this data.

4. (2 pts.)Plot the regression line on the same set of axes as the scatter diagram.

Answer 1

The equation has the form = a + bX ,

where Y is the dependent varible, X is the independent variable , 'b' is the slope of the line, and 'a' is the y-intercept

FORMULA :

CORRELATION COEFFICIENT :

i)

ii)

iii)

Regression line :

= a + bX ,

a =46.26064

b = 6.90957

iv)

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