AGBM 320 midterm Question and
answers 100% correct
We have collected the population of a random variable, the observed
outcomes are -3, 0, and 3. What is the population variance? - correct answer
✔(-3^2 + 0^2 + 3^2)/(3) = 6
Corn, Soybean, and Wheat prices have steadily decreased since 1970. -
correct answer ✔False
Corn, Soybean, and Wheat yields have generally increased since 1970. -
correct answer ✔True- yields (production per acre) have consistently
increased since 1970 due to increases in production technology
Which statement best summarizes the purpose of the standard error? -
correct answer ✔The standard error summarizes the dispersion of a sample
statistic around the population statistic.
Which statement below best summarizes the purpose of standard deviation? -
correct answer ✔The standard deviation summarizes the dispersion of the
observations within a data set around average outcome.
Pickle price returns follow the normal distribution. The average pickle price
return is 0% and the standard deviation is 10%. What is the upper 95%
confidence level limit for pickle price returns? - correct answer ✔19.6% for
normal distribution the upper 95% limit = average + 1.96*standard deviation
We have collected the a sample of data of a random variable, the outcomes
are -3,0,3. What is the sample variance? - correct answer ✔(-3^2 + 0^2 +
3^2)/(3-1) = 9
, If two random variables have negative covariance then the two variables will
have negative correlation coefficient. - correct answer ✔True :The correlation
coefficient is the covariance divided by the product of the standard deviations
thus if the covariance is negative the correlation must also be negative
because the standard deviations are always positive.
Todays price is $10, yesterdays price was $8, the natural log price return
between yesterday and today is? - correct answer ✔22.3% ln return = ln(p
today) - ln(p yesterday) = ln(10) - ln(8) = 22.3%
Two different student height regression models are estimated. Each model is
trying to explain the same y variable using the same sample of data, the
models differ in which x variables were used to explain the y variable. Model
#1 used age as the x variable and has a SSE of 100 while Model #2 used
race as the x variable and has a SSE of 110. Which model is the most
accurate? - correct answer ✔Model #1 The lower the SSE the better, we can
compare the models because they have the same y variable and the same
data sample.
Random variables x1 and y have a correlation coefficient of 0.0001. Random
variables x2 and y have a correlation coefficient of 0.95. If you were going to
run a regression with y as the dependent variable and could only use on x
variable would you recommend using x1 or x2? (choose the best answer) -
correct answer ✔x2
A regression model is estimated the results are predicted y = 23 + 7*x. The
random variable x is a dummy variable for gender and WOMEN are coded as
1, there are 11 men in the sample and 9 women in the sample. What is the
overall average of the y variable? - correct answer ✔Since the average for
the dummy variable must be 9/20 = 0.45. A regression model stores
averages, the overall average y outcome must be average y = 23 + 7*0.45 =
26.15.
answers 100% correct
We have collected the population of a random variable, the observed
outcomes are -3, 0, and 3. What is the population variance? - correct answer
✔(-3^2 + 0^2 + 3^2)/(3) = 6
Corn, Soybean, and Wheat prices have steadily decreased since 1970. -
correct answer ✔False
Corn, Soybean, and Wheat yields have generally increased since 1970. -
correct answer ✔True- yields (production per acre) have consistently
increased since 1970 due to increases in production technology
Which statement best summarizes the purpose of the standard error? -
correct answer ✔The standard error summarizes the dispersion of a sample
statistic around the population statistic.
Which statement below best summarizes the purpose of standard deviation? -
correct answer ✔The standard deviation summarizes the dispersion of the
observations within a data set around average outcome.
Pickle price returns follow the normal distribution. The average pickle price
return is 0% and the standard deviation is 10%. What is the upper 95%
confidence level limit for pickle price returns? - correct answer ✔19.6% for
normal distribution the upper 95% limit = average + 1.96*standard deviation
We have collected the a sample of data of a random variable, the outcomes
are -3,0,3. What is the sample variance? - correct answer ✔(-3^2 + 0^2 +
3^2)/(3-1) = 9
, If two random variables have negative covariance then the two variables will
have negative correlation coefficient. - correct answer ✔True :The correlation
coefficient is the covariance divided by the product of the standard deviations
thus if the covariance is negative the correlation must also be negative
because the standard deviations are always positive.
Todays price is $10, yesterdays price was $8, the natural log price return
between yesterday and today is? - correct answer ✔22.3% ln return = ln(p
today) - ln(p yesterday) = ln(10) - ln(8) = 22.3%
Two different student height regression models are estimated. Each model is
trying to explain the same y variable using the same sample of data, the
models differ in which x variables were used to explain the y variable. Model
#1 used age as the x variable and has a SSE of 100 while Model #2 used
race as the x variable and has a SSE of 110. Which model is the most
accurate? - correct answer ✔Model #1 The lower the SSE the better, we can
compare the models because they have the same y variable and the same
data sample.
Random variables x1 and y have a correlation coefficient of 0.0001. Random
variables x2 and y have a correlation coefficient of 0.95. If you were going to
run a regression with y as the dependent variable and could only use on x
variable would you recommend using x1 or x2? (choose the best answer) -
correct answer ✔x2
A regression model is estimated the results are predicted y = 23 + 7*x. The
random variable x is a dummy variable for gender and WOMEN are coded as
1, there are 11 men in the sample and 9 women in the sample. What is the
overall average of the y variable? - correct answer ✔Since the average for
the dummy variable must be 9/20 = 0.45. A regression model stores
averages, the overall average y outcome must be average y = 23 + 7*0.45 =
26.15.
