ECO 391 Final Exam questions well
answered graded A+
A regression's R^2 can never be smaller than its adjusted R^2 - correct answer ✔✔TRUE
The sum of Squared Residuals (SSE) is the variation in the data that is explained by our model -
correct answer ✔✔FALSE
A 95% confidence interval is larger (has a bigger range) than a 90% confidence interval all else
constant - correct answer ✔✔TRUE
In the simple regression model, X is a response or dependent variable - correct answer
✔✔FALSE
If the null hypothesis is H0: B1≥0, then we are doing the right tailed hypothesis test. - correct
answer ✔✔FALSE
The Standard Normal Distribution has a mean, median, and mode of 0. - correct answer
✔✔TRUE
As our F-statistic decreases closer to zero, we are more likely to reject the null hypothesis -
correct answer ✔✔FALSE
Standard Deviation is a measure of the variation of the data series. - correct answer ✔✔TRUE
A survery that only asks democrats "Who do you think will win the local election" is an example
of non-response bias - correct answer ✔✔FALSE
,Heteroskedasticity is when you X variable is correlated with your Y variable - correct answer
✔✔FALSE
Stratified Sampling is generally more accurate than cluster sampling and is preferred when
possible - correct answer ✔✔TRUE
In a simple linear regression, if we can reject the null hypothesis of an F-test, we can also be
certain that our only independent variable is statistically significant - correct answer ✔✔TRUE
The sample variance can be positive or negative - correct answer ✔✔FALSE
Imagine that the length of a newborn dragon, X, is normally distributed with the mean of u=6
inches and the standard deviation o=1.5 inches. What is the probability that the baby dragon
will be smaller than 3 inches? - correct answer ✔✔0.0228
Target sells a coat for $200 normally. You have $10 off coupon and they are running a 20% off
sale. If the cashier takes the coupon off first before applying the sale, how much will the coat
cost (pre-tax)? - correct answer ✔✔$152
In order to test the joint significance of our model as a whole, which of the following would we
do? - correct answer ✔✔Run the regression and interpret the significance of the F-statistic.
Which of the following is true about a mode? - correct answer ✔✔A dataset can have multiple
modes only if there is more than one observation
If we run a simple linear regression and find an R^2=0.45, we can conclude which of the
following? - correct answer ✔✔The variation in X explains 45% of the variation in Y
, After you graph the data, you realize that there is a large left tail. Knowing this, which value will
be larger: the mean or median? - correct answer ✔✔Median
Which of the following will increase the width of a confidence interval? - correct answer
✔✔decrease the sample size
Which statement about homoscedasticity is correct? - correct answer ✔✔is when the standard
errors do not depend on the values of the X's
Suppose you run a multiple regression model with 4 independent variables. If there are 100
observation and the SSE=75, what is the MSE? - correct answer ✔✔0.789
What is the predicted GPA for a male student who is 20 years old and averages 8 hours of sleep
each night? - correct answer ✔✔2.911
In a simple linear regression model, we find that B1 is not significantly different from zero.
Which of the following can we conclude? - correct answer ✔✔There is no evidence of a linear
relationship between X and Y.
Which of the following could be an example of autocorrelation? - correct answer ✔✔Removing
"Brick" from the model and running again
High levels of multi9collinearity make each of the following unreliable except: - correct answer
✔✔point estimate
The adjusted multiple coefficient of determination (the adjsted R^2) is adjusted for - correct
answer ✔✔the number of independent variables
On the basis of sample information, we either "accept the null hypothesis" or "reject the null
hypothesis" - correct answer ✔✔FALSE
answered graded A+
A regression's R^2 can never be smaller than its adjusted R^2 - correct answer ✔✔TRUE
The sum of Squared Residuals (SSE) is the variation in the data that is explained by our model -
correct answer ✔✔FALSE
A 95% confidence interval is larger (has a bigger range) than a 90% confidence interval all else
constant - correct answer ✔✔TRUE
In the simple regression model, X is a response or dependent variable - correct answer
✔✔FALSE
If the null hypothesis is H0: B1≥0, then we are doing the right tailed hypothesis test. - correct
answer ✔✔FALSE
The Standard Normal Distribution has a mean, median, and mode of 0. - correct answer
✔✔TRUE
As our F-statistic decreases closer to zero, we are more likely to reject the null hypothesis -
correct answer ✔✔FALSE
Standard Deviation is a measure of the variation of the data series. - correct answer ✔✔TRUE
A survery that only asks democrats "Who do you think will win the local election" is an example
of non-response bias - correct answer ✔✔FALSE
,Heteroskedasticity is when you X variable is correlated with your Y variable - correct answer
✔✔FALSE
Stratified Sampling is generally more accurate than cluster sampling and is preferred when
possible - correct answer ✔✔TRUE
In a simple linear regression, if we can reject the null hypothesis of an F-test, we can also be
certain that our only independent variable is statistically significant - correct answer ✔✔TRUE
The sample variance can be positive or negative - correct answer ✔✔FALSE
Imagine that the length of a newborn dragon, X, is normally distributed with the mean of u=6
inches and the standard deviation o=1.5 inches. What is the probability that the baby dragon
will be smaller than 3 inches? - correct answer ✔✔0.0228
Target sells a coat for $200 normally. You have $10 off coupon and they are running a 20% off
sale. If the cashier takes the coupon off first before applying the sale, how much will the coat
cost (pre-tax)? - correct answer ✔✔$152
In order to test the joint significance of our model as a whole, which of the following would we
do? - correct answer ✔✔Run the regression and interpret the significance of the F-statistic.
Which of the following is true about a mode? - correct answer ✔✔A dataset can have multiple
modes only if there is more than one observation
If we run a simple linear regression and find an R^2=0.45, we can conclude which of the
following? - correct answer ✔✔The variation in X explains 45% of the variation in Y
, After you graph the data, you realize that there is a large left tail. Knowing this, which value will
be larger: the mean or median? - correct answer ✔✔Median
Which of the following will increase the width of a confidence interval? - correct answer
✔✔decrease the sample size
Which statement about homoscedasticity is correct? - correct answer ✔✔is when the standard
errors do not depend on the values of the X's
Suppose you run a multiple regression model with 4 independent variables. If there are 100
observation and the SSE=75, what is the MSE? - correct answer ✔✔0.789
What is the predicted GPA for a male student who is 20 years old and averages 8 hours of sleep
each night? - correct answer ✔✔2.911
In a simple linear regression model, we find that B1 is not significantly different from zero.
Which of the following can we conclude? - correct answer ✔✔There is no evidence of a linear
relationship between X and Y.
Which of the following could be an example of autocorrelation? - correct answer ✔✔Removing
"Brick" from the model and running again
High levels of multi9collinearity make each of the following unreliable except: - correct answer
✔✔point estimate
The adjusted multiple coefficient of determination (the adjsted R^2) is adjusted for - correct
answer ✔✔the number of independent variables
On the basis of sample information, we either "accept the null hypothesis" or "reject the null
hypothesis" - correct answer ✔✔FALSE
