The correlation between two variables is –0.63 for a sample of 20 observations. what is the coefficient of determination between the two variables? 0.63 0.3969 0 .7937 we can’t determine it because sample size is smaller than 30.

b) 0.3969

Step-by-step explanation:

Given that the correlation between two variables is –0.63 for a sample of 20 observations.

Correlation is the measure of linear association between two variables.  Normally this varies from -1 to 1 . Here this is given as -0.63

Coefficient of determination has to be found out

Coefficient of determination, being the cause of variation caused by one variable on another is obtained by square correlation coefficient.

Hence coefficient of determination =

Hence correct option is option b) 0.3969

38.5

step-by-step explanation:

lets say, first number = r

second number = 3r+7

total = 49

(r)+(3r+7)= 49

4r+7 = 49

4r = 42

r = 42/4

r= 10.5

3r+7 = 3(10.5)+7 = 38.5

hope this

225x²+4=0

225x²=0-4

225x²=-4

x²=-4/225

x=±√-4/225