Answer:
C. About 18 percent of the variation in blood pressure can be explained by a linear relationship between blood pressure and caffeine consumed.
Explanation:
Here, r = 0.428
∴ We can say it will give a positive curve, as 0.428 indicates it is a positive correlation.
Though the amount of correlation is low, still it is positive and more than 0.4
So, nearly about 18% of the variation in the blood pressure can be observed by the consumption of caffeine water. As consumption of caffeine water and blood pressure is both increasing so we can say that r= 0.428 will give a positive linear curve.
