The covariance of data series is -10, while the variances of the two variables are, 64 and 25.
What is the correlation coefficient?
The covariance of data series is -10, while the variances of the two variables are, 64...
Calculating covariance and correlation for two sets of test scores. Basically, I'm given sample data for two sets of test scores. Each set has 17 scores. So, the table looks like: SERIES A: Score1, Score2.......Score17 SERIES B: Score1, Score2.......Score17 How would I go about measuring covariance? I know I need an x variable and a y variable -- but I thought covariance measured the relationship between the variables. Would x be series A and y be series B?
If the correlation coefficient between two variables is 0.5 and the standard deviation of the variables is 5 and 10, respectively, then the sample covariance is approximately ... a. 25 b. 50 c. 250 d. Impossible to determine with any level of accuracy.
Two random variables, X and Y, have the following variances: σ,-9 and σ-25 . If their correlation coefficient is 0.5, determine the following 5. (a) the variance of the random variable W 2X+ 3Y b) the variance of the random variable U-3X- Y
Covariance and correlation between two variables are reported in the same units. True False
In the effort to understand a relationship between two variables, correlation is an improvement over covariance, and simple regression is an improvement over correlation. Write a essay in which you explain covariance, correlation, and simple regression and why each would be preferred over the one before it. Use an imagined high school class as the target audience of your explanation.
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)
Consider the following sample data for two variables. IC x 4 2 2 16 y 9 10 16 5 311 a. Calculate the sample covariance b. Calculate the sample correlation coefficient. c. Describe the relationship between x and y ell 1( a. S xy Round to two decimal places as needed) hi
Explain briefly what is meant by linear correlation between two variables. Use a graph if necessary. (4) (b) If the data below represent the number of years of study and the wage earned by a sample of 10 women, calculate: i. the covariance of the two variables; (2) ii. the coefficients of variation of the two variables; and (2) iii. the variances of the two variables. (2) [10] Person Years of study Wage (R'000s) 1 2 3 4 5 6...
Two random variables X and Y have means E[X] = 1 and E[Y] = 0, variances 0x2 = 9 and Oy2 = 4, and a correlation coefficient xx =0.6. New random variables are defined by V = -2X + Y W = 2X + 2Y Find the means of V and W Find the variances of V and W defined in question 3 Find Rww for the variables V and W defined in question 3
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...