Which of the following statements are true? select all that apply.
1)the correlation coefficient gives us information as to how strong the linear association is between two quantitative variables
2) the correlation coefficient has units of measurement and does always lie between -1.0 and +1.0
3) the closer the absolute value of r is to 1, the stronger the relationship is between the two variables.
4) a correlation coefficient of r=0 indicates a strong linear relationship between two variables.
5) a correlation coefficient of r=-0.9 indicates a weak linear relationship between two variables
6) two variables can be correlated without one causing the other