ECO 391 Exam 1 Questions with Correct Answers 100% Pass
A local courier service advertises that its average delivery time is less than 6 hours for local deliveries.
When testing the two hypotheses, H0: μ ≥ 6 and HA: μ < 6, μ stand for ________. - Answers the mean
delivery times
What is Population Parameter? - Answers measures are computed from a population
What is Sample Statistic? - Answers measure estimated from data of a sample.
A Sample Statistic is referred to as the _______ - Answers point estimator of the population parameter.
Variance - Answers the average of squared differences b/w each data value and mean
-used when comparing 2 or more variables
Standard Deviation - Answers The positive Square Root of Variance
Coefficient of Variance - Answers indicates how large the standard deviation is in relation to the mean
What is mean? - Answers average of all values
The Sample Mean ( XBar) is the point estimator for the - Answers population Mean mu
What is Median? - Answers -value in the middle when values are in ascending order
-most used in property data and annual income
why? extreme property values can inflate the mean
What is Mode? - Answers Value that occurs with the greatest frequency
Bidmodal: Exactly 2 modes
Multimodal: more than 2 modes
Measure of Variability aka Dispersion, considers what 2 things? - Answers -avg delivery time
-variability in delivery time
What is Range? - Answers difference b/w largest value and smallest value
-simplest measure of variability
What are the 2 branches of Statistics? - Answers descriptive and inferential
Desrciptives statistics - Answers brief descriptive coefficients that summarize a given data set, which can
either be a representation of entire population
, inferential statistics - Answers used by random sample of data from population to describe and make
inferences about population
What is a Sampling Bias and what are 2 parts of it? - Answers the tendency of a sample statistic to
systematically over- or underestimate a population parameter.
-Selection and Nonresponse
What is a Selection Bias? - Answers A systematic exclusion of certain groups from consideration for the
sample. The sample is not representative of the population intended to be analyzed.
What is Non Response Bias? - Answers a systematic difference in preferences b/w respondents and non
respondents to a survey or poll
What is a population? - Answers consists of all items of interest in a statistical problem.
The Population Parameter is usually - Answers unknown
What is a Sample? - Answers The subset of a population
What is a Sample Statistic? - Answers calculated from sample and can be used to make inferences about
population
A survey that targets an entire population is called a - Answers Census
What are Sampling Methods? (5) - Answers 1. Simple Sampling
2. Convenience Sampling
3. Systematic Sampling
4. Cluster Random Sampling
5. Stratified Random Sampling
What is Simple Random Sampling? - Answers a sample of n observation that has the same probability of
being selected from the population as any other sample of n observations.
Adv: unbiased
Dis: we hope it is a representative sample
What is Convenience Sampling? - Answers Randomly surveying people (student walking on campus,
people walking in shopping mall,
Adv: convenient and cheap
A local courier service advertises that its average delivery time is less than 6 hours for local deliveries.
When testing the two hypotheses, H0: μ ≥ 6 and HA: μ < 6, μ stand for ________. - Answers the mean
delivery times
What is Population Parameter? - Answers measures are computed from a population
What is Sample Statistic? - Answers measure estimated from data of a sample.
A Sample Statistic is referred to as the _______ - Answers point estimator of the population parameter.
Variance - Answers the average of squared differences b/w each data value and mean
-used when comparing 2 or more variables
Standard Deviation - Answers The positive Square Root of Variance
Coefficient of Variance - Answers indicates how large the standard deviation is in relation to the mean
What is mean? - Answers average of all values
The Sample Mean ( XBar) is the point estimator for the - Answers population Mean mu
What is Median? - Answers -value in the middle when values are in ascending order
-most used in property data and annual income
why? extreme property values can inflate the mean
What is Mode? - Answers Value that occurs with the greatest frequency
Bidmodal: Exactly 2 modes
Multimodal: more than 2 modes
Measure of Variability aka Dispersion, considers what 2 things? - Answers -avg delivery time
-variability in delivery time
What is Range? - Answers difference b/w largest value and smallest value
-simplest measure of variability
What are the 2 branches of Statistics? - Answers descriptive and inferential
Desrciptives statistics - Answers brief descriptive coefficients that summarize a given data set, which can
either be a representation of entire population
, inferential statistics - Answers used by random sample of data from population to describe and make
inferences about population
What is a Sampling Bias and what are 2 parts of it? - Answers the tendency of a sample statistic to
systematically over- or underestimate a population parameter.
-Selection and Nonresponse
What is a Selection Bias? - Answers A systematic exclusion of certain groups from consideration for the
sample. The sample is not representative of the population intended to be analyzed.
What is Non Response Bias? - Answers a systematic difference in preferences b/w respondents and non
respondents to a survey or poll
What is a population? - Answers consists of all items of interest in a statistical problem.
The Population Parameter is usually - Answers unknown
What is a Sample? - Answers The subset of a population
What is a Sample Statistic? - Answers calculated from sample and can be used to make inferences about
population
A survey that targets an entire population is called a - Answers Census
What are Sampling Methods? (5) - Answers 1. Simple Sampling
2. Convenience Sampling
3. Systematic Sampling
4. Cluster Random Sampling
5. Stratified Random Sampling
What is Simple Random Sampling? - Answers a sample of n observation that has the same probability of
being selected from the population as any other sample of n observations.
Adv: unbiased
Dis: we hope it is a representative sample
What is Convenience Sampling? - Answers Randomly surveying people (student walking on campus,
people walking in shopping mall,
Adv: convenient and cheap
