ECO 391 Final Exam 1 Questions and
All Correct Answers 2025-2026
Updated.
Stratified sampling is generally more accurate than cluster sampling. - Answer True
The null hypothesis should contain the statement you are hoping to prove. - Answer False
When performing regression analysis, a higher level of variance typically indicates a more
accurate model. - Answer False
A z-value of -1.83 represents: - Answer a corresponding x value that falls 1.83 standard
deviations below the mean
A standard normal distribution is a normal distribution with _____. - Answer a mean of 0 and
a standard deviation of 1
Which of the following setups correspond to a negative, one-tailed hypothesis test? - Answer
b. Ho: μ≥ 74.5
As a general guideline, the research hypothesis should be stated as the: - Answer alternative
hypothesis
The variance of a sample or a population cannot be _____ - Answer negative
Using the Standard Normal Distribution, find the probability that Z > 1. - Answer 0.1587
All of the following are discrete variables except - Answer a person's height
In the Standard Normal Distribution, which of the following is equivalent to the probability that
Z < -2? - Answer Prob(Z > 2)
The purpose of statistical inference is to provide information about the ____. - Answer
, 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? - Answer selection bias
A regression model that incorporates three independent variables to explain the variation in
one dependent variable is called ____. - Answer complex
Which of the following relationships might you expect to be negative? - Answer iters of
pesticide sprayed and number of insects on crops
Which of the following best describes a relationship that is stochastic? - Answer influenced by
some external "noise"
Why do researchers use sample statistics instead of population parameters? - Answer two
answers - 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 _____. - Answer mode, mean and 50th
percentile
The sample variance _____. - Answer could be smaller, equal to, or larger than the true value
of the population variance
In regression analysis, if the dependent variable is measured in dollars, the independent
variable ____. - Answer can be measure in any units
Which of the following has the highest value (Standard Normal Distribution)? - Answer Prob (Z
< 1)
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
_____. - Answer H0: p≥ .30 Ha: p < .30
If a hypothesis is rejected at the 5% level of significance, it _____. - Answer may or may not be
rejected at the 1% level
All Correct Answers 2025-2026
Updated.
Stratified sampling is generally more accurate than cluster sampling. - Answer True
The null hypothesis should contain the statement you are hoping to prove. - Answer False
When performing regression analysis, a higher level of variance typically indicates a more
accurate model. - Answer False
A z-value of -1.83 represents: - Answer a corresponding x value that falls 1.83 standard
deviations below the mean
A standard normal distribution is a normal distribution with _____. - Answer a mean of 0 and
a standard deviation of 1
Which of the following setups correspond to a negative, one-tailed hypothesis test? - Answer
b. Ho: μ≥ 74.5
As a general guideline, the research hypothesis should be stated as the: - Answer alternative
hypothesis
The variance of a sample or a population cannot be _____ - Answer negative
Using the Standard Normal Distribution, find the probability that Z > 1. - Answer 0.1587
All of the following are discrete variables except - Answer a person's height
In the Standard Normal Distribution, which of the following is equivalent to the probability that
Z < -2? - Answer Prob(Z > 2)
The purpose of statistical inference is to provide information about the ____. - Answer
, 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? - Answer selection bias
A regression model that incorporates three independent variables to explain the variation in
one dependent variable is called ____. - Answer complex
Which of the following relationships might you expect to be negative? - Answer iters of
pesticide sprayed and number of insects on crops
Which of the following best describes a relationship that is stochastic? - Answer influenced by
some external "noise"
Why do researchers use sample statistics instead of population parameters? - Answer two
answers - 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 _____. - Answer mode, mean and 50th
percentile
The sample variance _____. - Answer could be smaller, equal to, or larger than the true value
of the population variance
In regression analysis, if the dependent variable is measured in dollars, the independent
variable ____. - Answer can be measure in any units
Which of the following has the highest value (Standard Normal Distribution)? - Answer Prob (Z
< 1)
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
_____. - Answer H0: p≥ .30 Ha: p < .30
If a hypothesis is rejected at the 5% level of significance, it _____. - Answer may or may not be
rejected at the 1% level
