Question

A) Two variables have a high covariance. This means the two variables have a strong relationship. T/F

B) For a variable x, the sample mean is 8 and the sample standard deviation is 2. One of the observations is 15. Is this observation an outlier?

Group of answer choices

Yes, the z-score is greater than 3

No, the z-score is between -3 and 3

Yes, the z-score is between -3 and 3

No, the z-score is less than -3

C) The correlation coefficient for two variables is -0.14. The relationship between the variables is

Group of answer choices

weak and positive

weak and negative

strong and positive

strong and negative

D)Two variables x and y have a strong positive correlation. This means

Group of answer choices

changing x will cause changes in y

changing y will cause changes in x

there may or may not be any causal relationship between x and y

None of these alternatives are correct

Answer 1

Part A)

Yes, higher covariance means stronger the relationship between variables.

Part B)

Standardizing the value
Z = ( X - µ ) / σ
Z = ( 15 - 8 ) / 2
Z = 3.5
Yes, the z-score is greater than 3

Part c)

r = - 0.14

It indicate that there is week correlation between variables, because the value is closer to 0.

Negative sign indicate that the correlation is negative

weak and negative

Part d)

If the variables have strong positive correlation, then we can conclude that changing x will cause changes in y.