AP Stats Section 3.1 Quiz

Of the following, which is true of the correlation coefficient, r?

• The value of r does not depend on the units of y and x.

• r = 0 indicates a perfect correlation between x and y.

• r cannot be less than 0 or greater than 1.

• The value of r depends on which of two variables is labeled x.

Consider the following five scatterplots. All are drawn to the same scale on both the x and y axes. For which scatterplot is the relationship negative?

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The breeding success of birds that nest on the ground can be affected by the depth of winter snow in high altitudes. The plot below relates the percentage of White-tailed Ptarmigan hens hatching at least one egg, to the amount of snowfall in the Sierra Nevadas that winter.

Which of the following is a reasonable % Nest Success for a 350cm Snow Depth

• 25

• 10

• 40

• 55

Other things being equal, larger automobile engines are less fuel-efficient. You are planning an experiment to study the effect of engine size (in liters) on the fuel efficiency (in miles per gallon) of sport utility vehicles. In this study,

• gas mileage is a response variable, and you expect to find a negative association.

• gas mileage is a response variable, and you expect to find a positive association.

• gas mileage is an explanatory variable, and you expect to find a strong negative association.

• gas mileage is an explanatory variable, and you expect to find a strong positive association.

• gas mileage is an explanatory variable, and you expect to find very little association.

Tags

CCSS.HSS.ID.B.6

CCSS.HSS.ID.C.7

CCSS.HSS.ID.C.8

The correlation between the heights of fathers and the heights of their (fully grown) sons is r = 0.52. This value was based on both variables being measured in inches. If fathers' heights were measured in feet (one foot equals 12 inches), and sons' heights were measured in furlongs (one furlong equals 7920 inches), the correlation between heights of fathers and heights of sons would be

• much smaller than 0.52

• slightly smaller than 0.52

• unchanged: equal to 0.52

• slightly larger than 0.52

• much larger than 0.52

All but one of the following statements contains an error. Which statement could be correct?

• There is a correlation of 0.54 between the position a football player plays and his weight.

• We found a correlation of r = –0.63 between gender and political party preference.

• The correlation between the distance travelled by a hiker and the time spent hiking is r = 0.9 meters per second.

• We found a high correlation between the height and age of children: r = 1.12.

• The correlation between mid-August soil moisture and the per-acre yield of tomatoes is r = 0.53.

Tags

CCSS.HSS.ID.B.6

CCSS.HSS.ID.C.8

CCSS.HSS.ID.C.9

What type of relationship does this graph have?

• Positive 
• Negative
• No Relationship
• Constant

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CCSS.HSS.ID.B.6

Describe the correlation coefficient if

r = 0.90

• Positive, weak

• Positive, strong

• Negative, weak

• Negative, strong

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CCSS.HSS.ID.B.6

CCSS.HSS.ID.C.8

Describe the correlation, if the correlation coefficient is r = -0.26

• Positive, weak

• Negative, weak

• Positive, strong

• Negative, strong

Tags

CCSS.HSS.ID.C.8

Describe the relationship between the variables.

• no correlation
• strong positive correlation
• strong negative correlation
• weak positive correlation