The r-value is : C. -0.903
Step-by-step explanation:
Here you are required to calculate r-value which is the correlation coefficient.
Form a table as shown
x y xy x² y²
4 23 92 16 529
5 12 60 25 144
8 10 80 64 100
9 9 81 81 81
13 2 26 169 4
∑39 56 339 355 858
The formula to apply here is ;
r=n(∑xy)-(∑x)(∑y) ÷ √ {[n∑x²-(∑x)²] [n∑y²-(∑y)²] }
where n is the number of data set , n=5
∑x=39 , ∑y=56 , ∑xy=339 ,∑x²=355 ,∑y²=858
Substitute values in the formula;
r= 5(339)-(39*56) ÷ √ {[5(355)-39²] × [5 (858)-56²] }
r= -0.903
Learn More
Correlation coefficient :https://brainly.com/question/3494021
Keyword :r-value, data,three-decimal places
#LearnwithBrainly
