The following is a set of data from a sample of n= 11 items. Complete (a) through ©
X 38 28 18 8 18 34 22 26 20 28 8
Y 19 14 9 4 9 17 11 13 10 14 4
a. Compute the covariance. (round to three decimal places as needed.)
b. Compute the coefficient of correlation.
The coefficient of correlation measures the relative strength of a linear relationship between two variables.
Compute the standard deviation for X. Round to six decimal places as needed
Compute the sample standard deviation for Y.
Compute the coefficient of correlation for X and Y,
c. How strong is the relationship between X and Y? Explain.
a positive correlation indicates that as one variable rises, the other variable also tends to rise.
a negative correlation indicates that as one variable rises, the other vaiable tends to fall.
a perfect correlation indicates that if a scatter plot were made, all points could be connected with a straight line. A
perfect positive correlation is a correlation of 1. a perfect negative correlation is a correlation of -1.
d.Use the information above, and the results for covariance and correlation, to decide what type of relationship and
how strong of a relationship, X and Y have.