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Name_________________________
M316 Elementary Statistics
Final Exam
Form A
v1
EID _________________________
Spring
2005
Instructor:
Dr. Gary Berg
Show all your work.
All problems are worth five points unless stated otherwise.
Part I
1)
The following data are the number of fire alarms answered by Boston Engine Company 10 over a 5day
period: 4, 3, 7, 4, 2. Calculate the variance and standard deviation for this data. (
Show your calculation
.)
2)
Circle the appropriate answer.
a)
Is the normal distribution
symmetric
or
skewed
?
b)
Which is the better data summary for a skewed distribution, the
fivenumber summary
or the
mean and standard deviation
?
c)
Is a pie chart better for
categorical
or
quantitative
data?
d)
Which is a resistant measure, the
mean
or the
median
?
e)
True
or
false
: the least squares regression line minimizes the sum of the squares of the residuals.
4)
True or False?
a)
Correlation does not imply causation.
True
False
b)
Influential observations (e.g. outliers) have little effect on the regression line.
True
False
c)
Residual plots help us assess the fit of a regression line.
True
False
d)
One of the variables measured and recorded in a study could be a lurking
variable.
True
False
e)
Extrapolation is the use of a regression line for prediction far outside the
range of values of the explanatory variable.
True
False
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3)
Suppose that some study finds the following. The explanatory variable
x
has an almost normal
distribution N(12, 3) with correlation
r
=0.8 on a response variable
y
, with distribution N(10, 2).
a)
Find the slope of the leastsquares regression line. (5points)
b)
Find the intercept of the leastsquares regression line. (5 points)
5)
A study in Sweden looked at former elite soccer players, people who played soccer but not at the elite
level, and people of the same age who did not play soccer. Here is a twoway table that classifies these subjects
by whether or not they had arthritis of the hip or knee by their mid50’s:
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