a) Correlation coefficient is -1
b .i) False as they are inversely related and the correlation is
negative
ii) It shows that the variables are independent of each other
4 a) Suppose Y X.Show in a diagram this function. What will be the correlation coefficient...
b) Show that x, -x)-o a) Suppose Y =-X . Show in a diagram this function, what will be the correlation coefficient between X and Y? 4 the correlation coefficient must b) i) If the covariance between two variables is be positive. True or False? suggest? i) If the covariance between two variables is zero, what does it 5 a) Define mutually exclusive events and independent events bi) For two events A and B (which are not mutually exclusive) complete...
4.he sample correlation coefficient between X and Y, rxy Sx/Sx S where S-the covariance between X and Ys Σ(X-XM) (-Yu)/ n-1 Sx the standard deviation of X and Sy the standard deviation of Y I) If the covariance is positive, the correlation coefficient must be positive: True or False? ii) If the covariance is negative, the correlation coefficient must be positive: True or False? a) ii) The correlation coefficient must lie between 0 and 1. True or False? v)lf the...
Suppose that two variables, x and y, have a correlation coefficient of 0.27. Which of the following statements are true? You must make a selection for each option. Click once to place a check mark for correct answers and click twice to empty the box for the wrong answers. The variables have a positive linear relationship. There is a weak relationship between these two variables. There is a strong relationship between these two variables As xincreases, y decreases. As x...
Find the covariance and correlation coefficient for the following sets of data. Select the answers equal to or closest to your results. X: 50 44 47 40 54 Y: 10 13 95 7 Cov What does each measure tell you? Check all that apply. The covariance tells you that there is a weak or nonexistent linear relationship between X and Y The covariance and correlation coefficient tell you that there is a positive linear relationship between X and Y. The...
A covariance coefficient is bounded between 1 and -1. True or False? A correlation of 1.0 means that a scatterplot of X and Y would result in all the values falling on a straight, downward sloping line. True or False?
If correlation coefficient between two random variables is zero, then it can be certain that they are also independent True False
Which of the following is false? Correlation coefficient and the slope always have the same sign (positive or negative). If the correlation coefficient is 1, then the slope must be 1 as well. Correlation measures the strength of linear association between two numerical variables. If the correlation between two variables is close to 0.01, then there is a very weak linear relation between them.
Let ρ represent the true population coefficient of correlation of two variables X and Y . Suppose you want to test the hypothesis that ρ = 0. Explain how you would test this hypothesis. [Hint: by the relationship between b1 and rXY ]
Determine whether each of the following statements regarding the correlation coefficient is true or false. The correlation coefficient equals the proportion of times that two variables lie on a straight line. The correlation coefficient will be +1.0 if all the data points lie on a perfectly horizontal straight line. The correlation coefficient measures the strength of any relationship that may be present between two variables. The correlation coefficient must always lie between –1.0 and +1.0.
True or false:1. The correlation coefficient and the covariance of two variables can have different signs. (True or False)2. Graphical analysis is a useful tool that allows the researcher to have an idea of the distribution of a data series. (True or False)3. A large data samples are usually normally distributed. (True or False)4. The standard deviation is always smaller than the variance. (True or False)