ECO 391 Exam 1 questions n answers
graded A+ 2025/2026
Stratified sampling is generally more accurate than cluster sampling. - correct answer ✔✔True
The null hypothesis should contain the statement you are hoping to prove. - correct answer
✔✔False
When performing regression analysis, a higher level of variance typically indicates a more
accurate model. - correct answer ✔✔False
A z-value of -1.83 represents: - correct answer ✔✔a corresponding x value that falls 1.83
standard deviations below the mean
A standard normal distribution is a normal distribution with _____. - correct answer ✔✔a mean
of 0 and a standard deviation of 1
Which of the following setups correspond to a negative, one-tailed hypothesis test? - correct
answer ✔✔b. Ho: μ≥ 74.5
As a general guideline, the research hypothesis should be stated as the: - correct answer
✔✔alternative hypothesis
The variance of a sample or a population cannot be _____ - correct answer ✔✔negative
Using the Standard Normal Distribution, find the probability that Z > 1. - correct answer
✔✔0.1587
, All of the following are discrete variables except - correct answer ✔✔a person's height
In the Standard Normal Distribution, which of the following is equivalent to the probability that
Z < -2? - correct answer ✔✔Prob(Z > 2)
The purpose of statistical inference is to provide information about the ____. - correct answer
✔✔population based on information within the sample
The measure of variation that is influenced most by extreme values is the _____. - correct
answer ✔✔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? - correct answer ✔✔selection bias
A regression model that incorporates three independent variables to explain the variation in
one dependent variable is called ____. - correct answer ✔✔complex
Which of the following relationships might you expect to be negative? - correct answer ✔✔iters
of pesticide sprayed and number of insects on crops
Which of the following best describes a relationship that is stochastic? - correct answer
✔✔influenced by some external "noise"
Why do researchers use sample statistics instead of population parameters? - correct answer
✔✔two answers - It is expensive to gather data on entire population and It is time consuming to
gather data on entire population
graded A+ 2025/2026
Stratified sampling is generally more accurate than cluster sampling. - correct answer ✔✔True
The null hypothesis should contain the statement you are hoping to prove. - correct answer
✔✔False
When performing regression analysis, a higher level of variance typically indicates a more
accurate model. - correct answer ✔✔False
A z-value of -1.83 represents: - correct answer ✔✔a corresponding x value that falls 1.83
standard deviations below the mean
A standard normal distribution is a normal distribution with _____. - correct answer ✔✔a mean
of 0 and a standard deviation of 1
Which of the following setups correspond to a negative, one-tailed hypothesis test? - correct
answer ✔✔b. Ho: μ≥ 74.5
As a general guideline, the research hypothesis should be stated as the: - correct answer
✔✔alternative hypothesis
The variance of a sample or a population cannot be _____ - correct answer ✔✔negative
Using the Standard Normal Distribution, find the probability that Z > 1. - correct answer
✔✔0.1587
, All of the following are discrete variables except - correct answer ✔✔a person's height
In the Standard Normal Distribution, which of the following is equivalent to the probability that
Z < -2? - correct answer ✔✔Prob(Z > 2)
The purpose of statistical inference is to provide information about the ____. - correct answer
✔✔population based on information within the sample
The measure of variation that is influenced most by extreme values is the _____. - correct
answer ✔✔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? - correct answer ✔✔selection bias
A regression model that incorporates three independent variables to explain the variation in
one dependent variable is called ____. - correct answer ✔✔complex
Which of the following relationships might you expect to be negative? - correct answer ✔✔iters
of pesticide sprayed and number of insects on crops
Which of the following best describes a relationship that is stochastic? - correct answer
✔✔influenced by some external "noise"
Why do researchers use sample statistics instead of population parameters? - correct answer
✔✔two answers - It is expensive to gather data on entire population and It is time consuming to
gather data on entire population
