Topic 5

Which of the following values ​​for the correlation coefficient indicates a high degree of inexact positive linear correlation between the two variables considered:

• 1

• 0.85

• 0.56

• -0.98

The maximum value of the covariance statistic is 1, which indicates an exact linear relationship between the two variables analyzed.

• True

• False

There are two variables X and Y. The covariance between them is 25.3, the variance of X is 12 and the variance of Y is 81. The value of the correlation coefficient between both variables is:

• 65.73

• 0.81

• 0.026

• Can't be estimated

The following regression line has been estimated between two variables X and Y: Y=200+7X. Indicate which of the following statements is incorrect.

• If X increases by one unit, Y will increase by 7 units

  
  

• If Y increases by one unit, X will increase by 7 units

  
  

• The value of the variable Y depends on the value of the variable X

• If X=0, the value of variable Y is equal to 200

  
  

There are two variables X and Y. The covariance between them is 30, the variance of X is 15 and the variance of Y is 81. The value of the coefficient b of the regression line Y=a+bX is equal to

• 1

• 2

• 3

• 0