91影视

$\stackrel{铃�}{Calculator}=鈭�1.2+0.865\left(Pencil\right)r=0.79$

A regression line is a straight line that depicts the relationship between an explanatory variable$x$ and a response variable$y$ By entering any value of $x$ into the equation of the line, you may use a regression line to anticipate the value of $y$ for any value of$x$

• The correlation would have remained the same if the student's explanatory variable had been the calculator. Because correlation $\left(r\right)$does not distinguish between explanatory and response variables, this assertion is correct. When computing the correlation, it doesn't matter which variable you name $X$and which you call $Y.$
• If the learner had used a calculator as the explanatory variable, the slope of the least-squares line would have remained the same. Because this statement is false. $Slope=r\frac{{蟽}_y}{{蟽}_X}$

If we change the explanatory and response variables, the slope value will change.

The number of correct answers on the paper and pencil quizzes had a higher standard deviation than the number of correct answers on the calculator quizzes." This assertion is untrue because

$$\begin{gathered} Slope=r\frac{{蟽}_{calculator}}{{蟽}_{pencil}} \\ 0.865=0.79脳\frac{{蟽}_{calculator}}{{蟽}_{pencil}} \\ 鈬�\frac{{蟽}_{calculator}}{{蟽}_{pencil}}=\frac{0.865}{0.79} \\ 1 \end{gathered}$$

If$\frac{{蟽}_{calculator}}{{蟽}_{pencil}}>1鈬�{蟽}_{calculator}>{蟽}_{pencil}$

On the calculator quizzes, the standard deviation of the number of right answers was higher than on the paper and pencil quizzes.