Chapter 3 AP Stats Logs

The following scatterplot describes the relationship between height (in cm) and foot length (also in cm) for 12 randomly selected students from the British Census @ Schools database. Which of the following is the best description of this relationship?

• There is some random variation, but otherwise height is directly proportional to foot length.
• There is a roughly linear relationship between height and foot length.
• There is a moderately weak, positive linear relationship between height and foot length.
• The relationship between height and foot length is linear, positive, and very strong.

Tags

CCSS.HSF.IF.B.4

Which of the following statements about the slope of the least-squares regression line is true? 

• It has the same sign as the correlation coefficient r.
• The square of the slope equals the proportion of the variation in the response variable that is explained by the explanatory variable.
• It is unitless.
• When the x-variable is 0, this is what the y-variable is predicted to be.

Tags

CCSS.HSS.ID.B.6

CCSS.HSS.ID.C.7

One of the following is a correct statement involving correlation. The other three contain blunders. Which one is correct? 

• The correlation between the gas mileage of a car and its weight is r = -0.71 gallon-pounds.
• The correlation between GPA and hours of sleep per night is r = 1.06.
• There is a correlation of r = 0.54 between the position a football player plays and his or her weight.
• The correlation between amount of fertilizer and pounds of tomatoes harvested was found to be r = 0.33.

Tags

CCSS.HSF.LE.B.5

A study showed that students who spend more time studying for statistics tests tend to achieve better scores on their tests. In fact, the number of hours studied turned out to explain 81% of the observed variation in test scores among the students who participated in the study. What is the value of the correlation between number of hours studied and test score? 

• r = 0.81
• r = 0.656
• r = 0.9
• There is no way to know.

Tags

CCSS.HSS.ID.B.6

CCSS.HSS.ID.C.8

CCSS.HSS.ID.C.9

The following computer output describes the relationship between y = height (in cm) and x = foot length (also in cm) for 12 randomly selected students from the British Census @ Schools database. The scatterplot for this relationship show a roughly linear shape. Which of the following is an equation of least-squares regression line for these data?

• Height = 117.99 + 1.878 (Foot Length)
• Foot Length = 117.99 + 1.878 (Height)
• Height = 1.878 + 117.99 (Foot Length)
• Foot Length = 1.878 + 117.99 (Height)

Tags

CCSS.8.EE.C.8C

Find  $y$   when  $x=3$  

 $\log y\ =1.3-0.25x$  

•  $y=0.55$  

•  $y=3.548$  

•  $y=3.29$  

•  $y=1956.658$  

Find  $x$   when  $y=3$  

 $\log y\ =1.3-0.25x$  

•  $y=0.55$  

•  $y=3.548$  

•  $y=3.29$  

•  $y=1956.658$  

Find $y$   when  $x=7.2$  
 $\log y=-0.24+\log x$  

•  $y=4.143$  

•  $y=0.617$  

•  $y=1.097$  

•  $y=12.512$  

Find $x$   when  $y=7.2$  
 $\log y=-0.24+\log x$  

•  $x=4.143$  

•  $x=0.617$  

•  $x=1.097$  

•  $x=12.512$  

 $9.3=x^{4.5}$  

Solve for x

•  $x=1.64$  

•  $x=0.215$  

•  $x=0.968$  

•  $x=0.653$