Data Set 6-1
The correlation between the number of PhDs and the number of mules in a state used to be approximately -.90. Accept the following simplified summary data.
$\begin{array}{lll}
& \underline{\text { PhDs}}& \underline{\text { Mules }}\
\text { Mean } & 40 & 200 \
\text { Standard Deviation } & 15 & 50
\end{array}$
In questions based on Data Set 6-1, the task is to predict the number of mules for a state, given the number of PhDs.
-The b coefficient in Data Set 6-1 is
A) -3.00
B) -0.27
C) 0.27
D) 3.00.

Question

Data Set 6-1
The correlation between the number of PhDs and the number of mules in a state used to be approximately -.90. Accept the following simplified summary data.
 $\begin{array}{lll}
& \underline{\text { PhDs}}& \underline{\text { Mules }}\
\text { Mean } & 40 & 200 \
\text { Standard Deviation } & 15 & 50
\end{array}$ 
In questions based on Data Set 6-1, the task is to predict the number of mules for a state, given the number of PhDs.
-The b coefficient in Data Set 6-1 is
A) -3.00
B) -0.27
C) 0.27
D) 3.00.

Quizplus · Accepted Answer

The b coefficient (slope of the regression line) can be calculated using the formula $b = r(\frac{s_y}{s_x})$, where $r$ is the correlation coefficient, $s_y$ is the standard deviation of the dependent variable (Mules), and $s_x$ is the standard deviation of the independent variable (PhDs). Given $r = -0.90$, $s_y = 50$, and $s_x = 15$, $b = -0.90(\frac{50}{15}) = -3$.

Data Set 6-1 the Correlation Between the Number of PhDs

Data Set 6-1
the Correlation Between the Number of PhDs