Economics 391 Dell chiesa Exam #1
questions well answered
True or False: Stratified sampling is generally more accurate than cluster sampling. - ANS
✔✔True
True or False: The null hypothesis should contain the statement you are hoping to prove. - ANS
✔✔False
True or False: When performing regression analysis, a higher level of variance typically indicates
a more accurate model. - ANS ✔✔False
A z-value of -1.83 represents: - ANS ✔✔a corresponding x value that falls 1.83 standard
deviations below the mean
A standard normal distribution is a normal distribution with: - ANS ✔✔a mean of 0 and a
standard deviation of 1
As a general guideline, the research hypothesis should be stated as the: - ANS ✔✔disproven
hypothesis
The variance of a sample or a population cannot be - ANS ✔✔less than 1
The purpose of statistical inference is to provide information about the - ANS ✔✔population
based on information within the population
The measure of variation that is influenced most by extreme values is the - ANS ✔✔range
,In an attempt to predict the outcome of a local election, a student travels around the UK
campus and only asks political science students who they would vote for. What type of bias will
this survey likely have? - ANS ✔✔selection bias
A regression model that incorporates three independent variables to explain the variation in
one dependent variable is called - ANS ✔✔complex
Which of the following relationships might you expect to be negative?
-Revolutions per minute and number of miles on tires
-liters of pesticide sprayed and number of insects on crops
-Weight and amount of sugar eaten per day - ANS ✔✔liters of pesticide sprayed and number of
insects on crops
Why do researchers use sample statistics instead of population parameters? - ANS ✔✔It is
expensive to gather data on entire population and It is time consuming to gather data on entire
population
The median of a sample will always equal the - ANS ✔✔50th percentile
The sample variance could be ___________ the true value of the population variance - ANS
✔✔smaller, equal to, or larger than
In regression analysis, if the dependent variable is measured in dollars, the independent
variable - ANS ✔✔can be measure in any units
, The school's newspaper reported that the proportion of students majoring in business is at least
30%. You plan on taking a sample to test the newspaper's claim. The correct set of hypotheses is
- ANS ✔✔H0: p ≥ .30
Ha: p < .30
If a hypothesis is rejected at the 5% level of significance, it - ANS ✔✔may or may not be
rejected at the 1% level
A meteorologist stated that the average temperature during July in Chattanooga was 76
degrees. A colleague says that might not be true. A sample of July temperatures over a 32-year
period was taken. The correct set of hypotheses is - ANS ✔✔H0: μ = 76
Ha: μ ≠ 76
An investment manager states that the average yearly rate of return on the stocks she
recommends is at least 15.0%. You plan on taking a sample to test her claim. The correct set of
hypotheses is - ANS ✔✔H0: μ ≥ 15.0%
Ha: μ < 15.0%
Suppose a sample regression equation is given by 𝑦̂ = 3 + 0.40x. Suppose when x is 10, y is
observed to be 8. What is the residual of the model prediction?
Does the model under or over predict the value of y? - ANS ✔✔1
the model under-predicts y
A regression analysis between sales (in $1000s) and price (in dollars) resulted in the following
equation:
= 50,000 − 8x
questions well answered
True or False: Stratified sampling is generally more accurate than cluster sampling. - ANS
✔✔True
True or False: The null hypothesis should contain the statement you are hoping to prove. - ANS
✔✔False
True or False: When performing regression analysis, a higher level of variance typically indicates
a more accurate model. - ANS ✔✔False
A z-value of -1.83 represents: - ANS ✔✔a corresponding x value that falls 1.83 standard
deviations below the mean
A standard normal distribution is a normal distribution with: - ANS ✔✔a mean of 0 and a
standard deviation of 1
As a general guideline, the research hypothesis should be stated as the: - ANS ✔✔disproven
hypothesis
The variance of a sample or a population cannot be - ANS ✔✔less than 1
The purpose of statistical inference is to provide information about the - ANS ✔✔population
based on information within the population
The measure of variation that is influenced most by extreme values is the - ANS ✔✔range
,In an attempt to predict the outcome of a local election, a student travels around the UK
campus and only asks political science students who they would vote for. What type of bias will
this survey likely have? - ANS ✔✔selection bias
A regression model that incorporates three independent variables to explain the variation in
one dependent variable is called - ANS ✔✔complex
Which of the following relationships might you expect to be negative?
-Revolutions per minute and number of miles on tires
-liters of pesticide sprayed and number of insects on crops
-Weight and amount of sugar eaten per day - ANS ✔✔liters of pesticide sprayed and number of
insects on crops
Why do researchers use sample statistics instead of population parameters? - ANS ✔✔It is
expensive to gather data on entire population and It is time consuming to gather data on entire
population
The median of a sample will always equal the - ANS ✔✔50th percentile
The sample variance could be ___________ the true value of the population variance - ANS
✔✔smaller, equal to, or larger than
In regression analysis, if the dependent variable is measured in dollars, the independent
variable - ANS ✔✔can be measure in any units
, The school's newspaper reported that the proportion of students majoring in business is at least
30%. You plan on taking a sample to test the newspaper's claim. The correct set of hypotheses is
- ANS ✔✔H0: p ≥ .30
Ha: p < .30
If a hypothesis is rejected at the 5% level of significance, it - ANS ✔✔may or may not be
rejected at the 1% level
A meteorologist stated that the average temperature during July in Chattanooga was 76
degrees. A colleague says that might not be true. A sample of July temperatures over a 32-year
period was taken. The correct set of hypotheses is - ANS ✔✔H0: μ = 76
Ha: μ ≠ 76
An investment manager states that the average yearly rate of return on the stocks she
recommends is at least 15.0%. You plan on taking a sample to test her claim. The correct set of
hypotheses is - ANS ✔✔H0: μ ≥ 15.0%
Ha: μ < 15.0%
Suppose a sample regression equation is given by 𝑦̂ = 3 + 0.40x. Suppose when x is 10, y is
observed to be 8. What is the residual of the model prediction?
Does the model under or over predict the value of y? - ANS ✔✔1
the model under-predicts y
A regression analysis between sales (in $1000s) and price (in dollars) resulted in the following
equation:
= 50,000 − 8x
