Refer to the accompanying scatterplot. a. Examine the pattern of all 10 points and subjectively determine whether there appears to be a strong correlation between x and y. b. Find the value of the correlation coefficient r and determine whether there is a linear correlation. c. Remove the point with coordinates (9,9)

and find the correlation coefficient r and determine whether there is a linear correlation. What do you conclude about the possible effect from a single pair ofvalues?

Critical Values for the Correlation Coefficient n alpha = .05 alpha = .01 4 0.95 0.99 5 0.878 0.959 6 0.811 0.917 7 0.754 0.875 8 0.707 0.834 9 0.666 0.798 10 0.632 0.765 11 0.602 0.735 12 0.576 0.708 13 0.553 0.684 14 0.532 0.661 15 0.514 0.641 16 0.497 0.623 17 0.482 0.606 18 0.468 0.59 19 0.456 0.575 20 0.444 0.561 25 0.396 0.505 30 0.361 0.463 35 0.335 0.43 40 0.312 0.402 45 0.294 0.378 50 0.279 0.361 60 0.254 0.33 70 0.236 0.305 80 0.22 0.286 90 0.207 0.269 100 0.196 0.256 Note: To test H subscript 0: rho equals 0 against H subscript 1: rho not equal to 0, reject H subscript 0 if the absolute value of r is greater than the critical value in the table.

Graph data points:

(1,1) (1,2) (1,3)

(2,1) (2,2) (2,3)

(3,1) (3,2) (3,3)

What is the value of the correlation coefficient for all 10 datapoints?

Is there a linear correlation between X and y= use 0.05 signficance

what is correlation when 9,9 is excluded

is there a linear correlation between x and y with exclusion

what can be concluded