# Following data represent of the preference of 10 students studying B.Sc(CSIT) towards two brands of  computer namely DELL and HP. Computer Student Preference Lenovo 5 2 9 8 1 10 3 4 6 7 Acer 10 5 1 3 8 6 2 7 9 4 Apply appropriate statistical tool to measure whether the brand preference is corelated. Also interpret your result.

 Lenovo(x) Acer(y) x2 y2 xy 5 10 25 100 50 2 5 4 25 10 9 1 81 1 9 8 3 64 9 24 1 8 1 64 8 10 6 100 30 60 3 2 9 4 6 4 7 16 49 28 6 9 36 81 54 7 4 49 16 28

n = 10

Now, Correlation Cofficient (r) is

= $$\frac{n \sum xy – \sum x \sum y }{\sqrt{n\sum x^2 – (\sum x)^2 } . \sqrt{n \sum y^2 – (\sum y)^2}}$$

= $$\frac{10 \times 277 – 55 \times 55 }{\sqrt{10 \times 385 – (55)^2 } . \sqrt{10 \times 385 – (55)^2}}$$

= $$\frac{-255}{28.723.28.723}$$

= -0.309

Hence, we can see that the brand preference is co-related and the correlation between the brands lenovo and acer is moderate negative correlation.