4.10 Regression line of x on y Quiz

1. The regression line of $x$ on $y$ is $x=0.5y+3$. Estimate $x$ when $y=20$.

• A. $13$
• B. $34$
• C. $8.5$
• D. $23$

2. The regression lines are $y=3x-4$ and $x=0.25y+2$. Find $\bar{x}$.

• A. $4$
• B. $8$
• C. $2$
• D. $-4$

3. A student wants to estimate a value of $y$ from a given value of $x$. Which line should be used?

• A. The regression line of $x$ on $y$
• B. The regression line of $y$ on $x$
• C. Either line; they are always the same
• D. The $x$ on $y$ line rearranged for $y$

4. For which value of $r$ do the two regression lines coincide?

• A. $r=0$
• B. $r=0.5$
• C. $r=-1$
• D. $r=0.99$

5. An $x$ on $y$ line was found from data with $y$ between 40 and 90 and $r=0.95$. For which given $y$ is the estimate of $x$ most reliable?

• A. $y=20$
• B. $y=65$
• C. $y=120$
• D. All are equally reliable