What is the value of the correlation coefficient r of the data set? ! ? will give brainliest answer : ) i am so lost options: -1 -0.81 0.66 0.81

The formula for the correlation coefficient is quite messy. I suggest checking some websites discussing this and am also attaching the formula how to calculate it by hand (the ∑'s mean summation over all the elements listed.

But unless your teacher does not allow using online calculators, you can use them. I used python's function to process the data in the table and the result is approximately -0.81. So that's your answer.

Negative value like -0.81 means that the variables x and y are quite "anit-correlated" meaning the value behave like opposites: when x is small, y tends to be large, and vice versa.  

Actually Welcome to the concept of Resistance,

R = PL/A

===> rearranging in terms of A will give us as,

===> A = PL/R