STA 2023 NEWEST ACTUAL EXAM 2 WITH COMPLETE
QUESTIONS AND COMPLETE SOLUTIONS //
VERIFIED//GRADED A+
Central Limit Theorem
Even when the population's probability distribution is
not bell shaped, the sampling distribution of the sample
mean is bell-shaped when the same size is large
enough (n≥30).
Population Distribution
The distribution for the overall population, which is
based on parameters such as the population mean and
the population standard deviation.
Data Distribution
The distribution of the data we collect in practice. We
collect samples in order to create a data distribution so
that we can estimate the population. The larger the
sample size, the more the better the data distribution
approximates the population distribution.
Page 1 of 19
,The data distribution looks more like the population
distribution when the sample size is (low/high).
high
Sample means tend to cluster more around the
population mean when the sample size is (low/high).
high
A _____ is a numerical summary of the data in a
population, and a _____ is a numerical summary of the
data in a sample.
parameter; statistic
Point Estimates
• Statistics that are used as "best guesses" for
parameters
• Sample mean point estimate for population mean
• Sample stdev. estimate for population stdev.
• Sample proportion point estimate for population
proportion
Page 2 of 19
, Interval Estimates
Describe a range over which we can reasonably
confident that the population parameter lies.
Bias vs. Variability
Biased: sampling distribution not centered at the
parameter of interest
Variability: sampling distribution has a large stderror
and this highly spread out
Inferential Statistics
The branch of statistics that uses sample statistics to
estimate population parameters.
Confidence Interval
Estimator ± Margin of Error
Estimator
Page 3 of 19
QUESTIONS AND COMPLETE SOLUTIONS //
VERIFIED//GRADED A+
Central Limit Theorem
Even when the population's probability distribution is
not bell shaped, the sampling distribution of the sample
mean is bell-shaped when the same size is large
enough (n≥30).
Population Distribution
The distribution for the overall population, which is
based on parameters such as the population mean and
the population standard deviation.
Data Distribution
The distribution of the data we collect in practice. We
collect samples in order to create a data distribution so
that we can estimate the population. The larger the
sample size, the more the better the data distribution
approximates the population distribution.
Page 1 of 19
,The data distribution looks more like the population
distribution when the sample size is (low/high).
high
Sample means tend to cluster more around the
population mean when the sample size is (low/high).
high
A _____ is a numerical summary of the data in a
population, and a _____ is a numerical summary of the
data in a sample.
parameter; statistic
Point Estimates
• Statistics that are used as "best guesses" for
parameters
• Sample mean point estimate for population mean
• Sample stdev. estimate for population stdev.
• Sample proportion point estimate for population
proportion
Page 2 of 19
, Interval Estimates
Describe a range over which we can reasonably
confident that the population parameter lies.
Bias vs. Variability
Biased: sampling distribution not centered at the
parameter of interest
Variability: sampling distribution has a large stderror
and this highly spread out
Inferential Statistics
The branch of statistics that uses sample statistics to
estimate population parameters.
Confidence Interval
Estimator ± Margin of Error
Estimator
Page 3 of 19
