The data below are the ages and systolic blood pressures (measured in millimeters of mercury)of 9 randomly selected adults. Calculate the correlation coefficient, r. $$\begin{array} { l | c | c | c | c | c | c | c | c | c | }
\text { Age, } \mathrm { x } & 33 & 36 & 40 & 43 & 46 & 48 & 52 & 56 & 60 \
\hline \text { Pressure, } \mathrm { y } & 112 & 116 & 119 & 127 & 138 & 141 & 144 & 146 & 148
\end{array}$$
A)0.960
B)0.998
C)0.890
D)0.908

Question

The data below are the ages and systolic blood pressures (measured in millimeters of mercury)of 9 randomly selected adults. Calculate the correlation coefficient, r. $$\begin{array} { l | c | c | c | c | c | c | c | c | c | } 
\text { Age, } \mathrm { x } & 33 & 36 & 40 & 43 & 46 & 48 & 52 & 56 & 60 \
\hline \text { Pressure, } \mathrm { y } & 112 & 116 & 119 & 127 & 138 & 141 & 144 & 146 & 148
\end{array}$$
A)0.960
B)0.998
C)0.890
D)0.908

Quizplus · Accepted Answer

The correlation coefficient, $r$, measures the strength and direction of a linear relationship between two variables. It can be calculated using the formula: $$r = \frac{n(\sum xy) - (\sum x)(\sum y)}{\sqrt{[n\sum x^2 - (\sum x)^2][n\sum y^2 - (\sum y)^2]}}$$ where $n$ is the number of pairs, $x$ and $y$ are the individual sample points. Calculating $r$ for the given data yields a value of approximately 0.960, indicating a very strong positive linear relationship between age and systolic blood pressure.

The Data Below Are the Ages and Systolic Blood Pressures