Which of the following is not the job of a statistician?
A) determining whether the conclusions drawn from a study are to be trusted
B) implementing new procedures based on the results of a study
C) collecting numerical information in the form of data
D) determining what information is relevant in a given problem
Q. 2Storks Data show that there is a positive association between the population of 17 European countries and the number of stork pairs in those countries.
a. Briefly explain what positive association means in this context.
b. Wildlife advocates want the stork population to grow, and jokingly suggest that citizens should be encouraged to have children. As a statistician, what do you think of this suggestion? Explain briefly.
Q. 3Two variables that are actually not related to each other may nonetheless have a very high correlation because they both result from some other, possibly hidden, factor. This is an example of
A) an outlier.
B) extrapolation.
C) regression.
D) leverage.
E) a lurking variable.
Q. 4A correlation of zero between two quantitative variables means that
A) re-expressing the data will guarantee a linear association between the two variables.
B) none of these
C) there is no association between the two variables.
D) there is no linear association between the two variables.
E) we have done something wrong in our calculation of r.
Q. 5Another company's sales increase by the same percent each year. This growth is . . .
A) logarithmic B) quadratic C) exponential D) power E) linear
Q. 6A company's sales increase by the same amount each year. This growth is . . .
A) linear B) exponential C) power D) quadratic E) logarithmic
Q. 7Which statement about influential points is true?
I. Removal of an influential point changes the regression line.
II. Data points that are outliers in the horizontal direction are more likely to be influential than points that are outliers in the vertical direction.
III. Influential points have large residuals.
A) I and III B) I only C) II and III D) I, II, and III E) I and II
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