Multiple Choice Identify the
choice that best completes the statement or answers the question.


1.

Suppose the following information was collected,
where X = diameter of tree trunk in inches, and Y = tree height in feet.
If the LSRL equation is y = –3.6
+ 3.1x, what is your estimate of the average height of all trees having a trunk diameter of 7
inches?


2.

A copy machine dealer has data on the number x of
copy machines at each of 89 customer locations and the number y of service calls in a month at each
location. Summary calculations give = 8.4, S_{x} = 2.1, = 14.2,
S_{y} = 3.8, and r = 0.86. What is the slope of the least squares regression line of
number of service calls on number of copiers?
a.  0.86  b.  1.56  c.  0.48  d.  None of
these 


3.

There is a linear relationship between the number
of chirps made by the striped ground cricket and the air temperature. A least squares fit of
some data collected by a biologist gives the model = 25.2 +
3.3x, where x is the number of chirps per minute and is the
estimated temperature in degrees Fahrenheit. What is the estimated increase in temperature that
corresponds to an increase in 1 chirp per minute?
a.  1.0 °F  b.  3.3 °F  c.  25.2
°F  d.  28.5 °F 


4.

A set of data relates the amount of annual salary
raise and the performance rating. The least squares regression equation is = 1,400 +
2,000x where y is the estimated raise and x is the performance rating. Which
of the following statements is not correct?
a.  The expected salary for a performance rating of 0 is
$1,400.  b.  For each increase of one point in performance rating,
the raise will increase on average by $2,000.  c.  The correlation
for of these two variables is positive.  d.  All of the above
are true. 


5.

Below is a scatterplot of the calories and sodium
content (in milligrams) of several brands of meat hot dogs. The leastsquares regression line has
been drawn on the plot. Based on the leastsquares
regression line in this scatterplot, one would predict that a hot dog containing 100 calories would
have a sodium content (in milligrams) of about



Scenario 33
Consider the following scatterplot, which describes
the relationship between stopping distance (in feet) and air temperature (in degrees Centigrade) for
a certain 2,000pound car travelling 40 mph.


6.

Use Scenario 33. The correlation between temperature and stopping
distance
a.  is approximately 0.9.  b.  is approximately 0.6.  c.  is approximately
0.0.  d.  is approximately 0.6. 


7.

Which of the following has a correlation that is closest to 0?


8.

Which of the following is NOT true about the correlation coefficient
r?
a.   b.  When the slope of
the data is negative, the correlation r will be negative  c.  Whenever all the
data lie on a perfectly straight line, the correlation r will always be equal to
+1.0  d.  Correlation is greatly affected by outliers 



The table below shows the temperature of a pot of water as it is being heated on
a stove. Time (min),
x  1  2  3  4  5  Temp (ºF), y  76  80  84  88  92       


9.

What is the predicted temperature of the water after 8 minutes?


10.

What was the temperature of the water before it was heated?
