Analyzing the behavior of unemployment rates across U.S. states in March
of 2006 is an example of using
cross-sectional data.
experimental data.
panel data.
time series data.
Ideal randomized controlled experiments are
often performed in practice
sometimes used by universities to determine who graduates in four
years rather than five
often used by the Federal Reserved to study the effects of monetary
policy
useful because they give a definition of a causal effect
The expected value of a discrete random variable
can be found by determining the 50% value in the c.d.f.
is the outcome that is most likely to occur.
is computed as a weighted average of the possible outcome of that
random variable, where the weights are the probabilities of that
outcome.
equals the population median.
Assume that Y is normally distributed N(μ ,σ 2 ) . Moving from the mean
(μ ) 1.96 standard deviations to the left and 1.96 standard deviations to
the right, then the area under the normal probability density function is
0.33
0.05
0.67
0.95
An estimator is
a random variable.
a formula that gives an efficient guess of the true population value.
an estimate.
a nonrandom number.
A scatterplot
relates the covariance of X and Y to the correlation coefficient.
shows n observations of Y over time.
is a plot of n observations on Xi and Yi , where each observation is
represented by the point (Xi ,Yi ) .
shows how Y and X are related when their relationship is scattered all
over the place.
Which of the following is not an example of unethical behavior on the part
of the regression user?
Predicting the dependent variable of interest with the willful intent of
possibly excluding certain independent variables from consideration in
the model.
Willfully removing independent variables from the model that exhibit a
high degree of multicollinearity.
Deleting observations from the model to obtain a better model without
giving reasons for deleting these observations.
Making inferences about the model without providing an evaluation of
the assumptions when he or she knows that the assumptions of least
squares regression are violated.
________ is a particular combination of levels of the factors involved in an
experiment.
The factor level
An analysis of variance
The sampling design
A treatment
Which 2-Way ANOVA F test should be conducted first?
A main effect
does not matter
interaction
B main effect
The logarithm transformation can be used
to change a linear independent variable into a nonlinear independent
variable.
to test for possible violations to the autocorrelation assumption.
to overcome violations to the autocorrelation assumption.
to change a nonlinear model into a linear model.
An independent variable Xj is considered highly correlated with the
other independent variables if
VIFj > VIFi for i ≠ j
VIFj < 5
VIFj > 5
VIFj < VIFi for i ≠ j
When you have two explanatory variables (one quantitative and one
categorical) that interact in a regression analysis how can you allow for the
interaction?
Fit a simple linear regression using only the variable with the highest
correlation to the response.
Fit separate regression lines for each category of the categorical
variable.
Use logistic regression.
Use indicator variables for the categorical variable.
Which of the following is always true?
If P(A and B) = 0 , then A and B are independent.
If A and B are disjoint, then they cannot be independent.
If A and B are independent, they must be disjoint.
If P(A and P) = P(A or B) , then A and B are independent.
If A and B are disjoint, P(A) + P(B) = 1
What scale of measurement is type of workplace injuries (slip and fall,
stress related, etc.)?
Quantitative
Interval
Nominal
Ordinal
Numerical
The following are all least squares assumptions with the exception of:
The conditional distribution of ui given Xi has a mean of zero.
The explanatory variable in regression model is normally distributed.
Large outliers are unlikely.
Using a computer to mimic what would actually happen if you selected a
sample and used statistics in real life is called
time series
database
random sampling
simulation
The manager of a natural foods grocery is considering the addition of a
play area and would like to know what percentage of its customers shop
with children under the age of 8. To obtain an estimate of this percentage,
one morning between 9:00 and 11:00 the cashiers record how many of their
customers have children under the age of 8 with them. What type of
sample does this represent?
A volunteer sample
A simple random sample
A census
A convenience sample
If A and B are mutually exclusive events with P(A) = 1/7 , P(B) = 2/7 ,
then P(A or B) equals
2/47.
0.
19/49.
3/7.
名詞解釋(25%,每題5%)
以下是五個與統計有關的英文專有名詞,請自行舉例說明每個名詞的意義。
1. Likelihood Function
2. Central Limit Theorem
3. Law of Large Number
4. Random Variable
5. i.i.d. (independently and identical distributed)
除了EXCEL 外,請開列兩種常用統計套裝軟體(英文簡稱即可)。(4%)
透過(市場)問卷調查的資料,是否適合用以探討研究變數之間的因果關係?為
什麼?(5%)
What would the correlation coefficient be if all observations for the two
variables were on a curve described by Y = X2 ? Why? (6%)
可觀看題目詳解,並提供模擬測驗!(免費會員無法觀看研究所試題解答)