$\left|\begin{array}{ccc}6&7&-1\\3&n&5\\9&11&n\end{array}\right| =0\\\\\\\\6(n^2-55)-3(7n+11)+9(35+n)=0\\\\n^2-2n-8=0\\\\\Delta=36=6^2\\\\n=\dfrac{2-6}{2} =-2\ or\ n=\dfrac{2+6}{2}=4\\$

4 0

2 years ago

Arianna gathered data about the distance of 20 cities from the equator and the average hours of sunlight per day in December for

stich3 [128]

Answer-

A. strong negative correlation.

Solution-

Direction of a relationship

Positive- If one variable increases, the other tends to also increase. If one decreases, the other tends to also. It is represented by positive numbers(i.e 0 to 1).
Negative- If one variable increases, the other tends to decrease, and vice-versa. It is represented by negative numbers(i.e 0 to -1)

Strength of a relationship

Perfect Relationship- When two variables are linearly related, the correlation coefficient is either 1 or -1. They are said to be perfectly linearly related, either positively or negatively.
No relationship- When two variables have no relationship at all, their correlation is 0.

As in this case, correlation coefficient was found to be -0.91, which is negative and close to -1, so it is a strong negative correlation.

5 0

2 years ago