Concept of Correlation Coefficient

Two series of x and y with 50 items each have standard deviations of 4.8 and 3.5 respectively. If the sum of products of deviations of x and y series from respective arithmetic means is 420, then find the correlation coefficient between x and y.

Given that r = 0.4, `sigma_"y"` = 3, `sum("x"_"i" - bar"x")("y"_"i" - bar"y")` = 108, `sum("x"_"i" - bar"x")^2` = 900. Find the number of pairs of observations.

If the correlation coefficient between x and y is 0.8, what is the correlation coefficient between x + 7 and y + 9

If the correlation coefficient between x and y is 0.8, what is the correlation coefficient between 2x and y

If the correlation coefficient between x and y is 0.8, what is the correlation coefficient between x – 5 and y – 3

Find correlation coefficient between x and y series for the following data.
n = 15, `bar"x"` = 25, `bar"y"` = 18, σ_x = 3.01, σ_y = 3.03, `sum("x"_"i" - bar"x") ("y"_"i" - bar"y")` = 122

The correlation coefficient between two variables x and y are 0.48. The covariance is 36 and the variance of x is 16. Find the standard deviation of y.

Given the following information, `sum"x"_"i"^2` = 90, `sum"x"_"i""y"_"i"` = 60, r = 0.8, `sigma_"y"` = 2.5, where x_i and y_i are the deviations from their respective means, find the number of items.