Question

A researcher is examining the relationship between the number of hours slept and score on a cognitive test, which method should be used to measure the linear relationship between these two variables?

a. Correlation
b. Proportion
c. Quartile
d. Standard deviation

Answer 1

The method that should be used to measure the linear relationship between the number of hours slept and score on a cognitive test is correlation.

Step-by-step explanation:

The method that should be used to measure the linear relationship between the number of hours slept and score on a cognitive test is correlation.

Correlation measures the strength and direction of the relationship between two variables. In this case, the researcher can calculate the correlation coefficient, which will indicate if there is a linear relationship between the number of hours slept and the cognitive test score.

The correlation coefficient ranges from -1 to +1. A positive value indicates a positive linear relationship, where an increase in the number of hours slept is associated with an increase in the cognitive test score. A negative value indicates a negative linear relationship, where an increase in the number of hours slept is associated with a decrease in the cognitive test score. A correlation coefficient of 0 indicates no linear relationship between the variables.

Answer 2

A

Step-by-step explanation:

Correlation shows the association between two variables for example x and y. A positive correlation means as x increases or decreases y equally increases or decreases while a negative correlation means as x increases, y decreases vice versa with correlation coefficient r between -1 ≤ r ≤ 1. Correlation with coefficient zero shows not relation with the two variables. As r approaches 1 the correlation approaches perfect positive correlation while as r approaches -1 the correlation approaches perfect negative correlation.

Correlation only show association but not tell whether x causes y or the situation is cause by some unseen third factor.