Stat, Chapter 3: Scatterplots, Correlation, & Regression

The height (in feet) and volume (in cubic feet) of usable lumber of 32 cherry trees are measured by a researcher. The goal is to determine if volume of usable lumber can be estimated from the height of a tree. 
In this study, the response variable is...

• height of researcher
• volume of lumber
• height of tree
• impossible to determine

Tags

CCSS.HSS.ID.C.9

Which of the following statements are supported by the scatterplot?
I.   There is a positive association between height and volume.
II.  There is an outlier in the plot. 
III.  As the height of a cherry tree increases, the volume of useable lumber it yields increases.

• I only
• II only
• I and II only
• I, II, and III

Tags

CCSS.HSF.IF.B.4

If the data point (65,70) were removed from this study, how would the value of the correlation r change?

• r would be smaller, since there are fewer data points.
• r would be smaller, because this point falls in the pattern of the rest of the data.
• r would be larger, since the x and y coordinates are larger than the mean x and mean y, respectively.
• r would be larger, since this point does not fall in the pattern of the rest of the data.

A study is conducted to determine if one can predict the yield of a crop based on the amount of fertilizer applied to the soil. 
The response variable in this study is...

• yield of the crop.
• amount of fertilizer applied to the soil.
• the experimenter.
• the soil.

Tags

CCSS.HSF-LE.A.1B

A researcher wishes to determine whether the rate of water flow (in liters per second) over an experimental soil bed can be used to predict the amount of soil washed away (in kilograms). 
In this study, the explanatory variable is...

• amount of eroded soil.
• rate of water flow.
• size of soil bed.
• depth of soil bed.

Tags

CCSS.HSF-LE.A.1B

Two variables are said to be negatively associated if...

• larger values of one variable are associated with larger values of the other.
• larger values of one variable are associated with smaller values of the other.
• smaller values of one variable are associated with smaller values of the other.
• smaller values of one variable are associated with both larger or smaller values of the other.

You would draw a scatterplot to...

• show the distribution of heights of students in this course.
• compare the distributions of heights for male and female students in this course.
• show the relationship between gender and having a driver’s license.
• show the relationship between the height of female students and the heights of their mothers.

A study of the effects of television on child development measured how many hours of television each of 125 grade school children watched per week during a school year and each child’s reading score. Which variable would you put on the horizontal axis of a scatterplot of the data?

• Reading score, because it is the response variable.
• Reading score, because it is the explanatory variable.
• Hours of television, because it is the response variable.
• Hours of television, because it is the explanatory variable.

The scatterplot shows that...

• countries that drink more wine have higher death rates from heart disease.
• the amount of wine a country drinks is not related to its heart disease death rate.
• countries that drink more wine have lower death rates from heart disease.
• heart disease deaths is the explanatory variable.

Which country is represented by the clear triangle in the scatterplot?

• New Zealand
• Canada
• Finland
• Belgium