Question

Consider the following bivariate data.

Point A B C D E F G H I J
x 3 4 2 1 7 2 1 0 4 2
y 1 7 3 3 6 6 5 0 6 2



(b) Calculate the covariance. (Give your answer correct to two decimal places.)


(c) Calculate sx and sy. (Give your answers correct to three decimal places.)
sx =
sy =

(d) Calculate r using formula 13.2. (Give your answer correct to two decimal places.)


(e) Calculate r using formula 13.3. (Give your answer correct to two decimal places.)

Answer 1

What did you get using the given formulas 13.2 and 13.3?

Answer 2

this is what I done and it was wrong mean of x = 2.6 sd = 2.01108, y mean 3.9, sd 2.42441; then I added the sd 4.43549/(2.011080)(2.42441) = 5.3471

c. I just added all the x together = 26
sy = 39 The formula for 13.2 is r=covar(xto the 1power and y to 1power)= covar (x,y)/Sx X Sy

13.3 formula is ss(xy)/ sqrt ss(x)*ss(y) and that I got 127/sqrt 26*205which I had for the y squared
and that I got 190.5 which was wrong.