EXST 2201 EXAM QUESTIONS AND ANSWERS WITH COMPLETE
SOLUTIONS 100% GUARANTEED PASS
Shape of sampling distribution of a sample average will always be..
bell shaped
if there are 30 data points, sampling distribution will be
bell shaped
< 30 data points means there will be an _____ shape
unknown
> 30 data points means there will be a _____ shape
bell
Best estimator for population mean?
sample average
what do you do first to find confidence interval
find critical values (width of interval)
Key requirement in estimating a population mean
the standard deviation is known
Characteristics of t-distribution
varies or depends on DF
mean= 0
symmetric distribution
t and Z nearly same for large samples
, calculate z-statistic when
the population standard deviation is known
calculate the t statistic when
population standard deviation is not known
the point estimate of the value mean is the
value of the sample average
the point estimate of the population standard deviation is the
value of the sample standard deviation
3 properties of good estimator
unbiased- expected value of estimator equals value of parameter
consistent- larger sample makes estimator more accurate
efficient- estimator has the smallest standard deviation
calculated from a large number of random samples that contain the value of the
population parameter
confidence level
the area outside of the region of confidence
significance level, denoted by a
in t statistic a/2 gives the
area in one tail (column of t-table)
in t statistic n-1 gives the
degrees of freedom (row of t-table)
the right term in a confidence interval estimate
margin of error
SOLUTIONS 100% GUARANTEED PASS
Shape of sampling distribution of a sample average will always be..
bell shaped
if there are 30 data points, sampling distribution will be
bell shaped
< 30 data points means there will be an _____ shape
unknown
> 30 data points means there will be a _____ shape
bell
Best estimator for population mean?
sample average
what do you do first to find confidence interval
find critical values (width of interval)
Key requirement in estimating a population mean
the standard deviation is known
Characteristics of t-distribution
varies or depends on DF
mean= 0
symmetric distribution
t and Z nearly same for large samples
, calculate z-statistic when
the population standard deviation is known
calculate the t statistic when
population standard deviation is not known
the point estimate of the value mean is the
value of the sample average
the point estimate of the population standard deviation is the
value of the sample standard deviation
3 properties of good estimator
unbiased- expected value of estimator equals value of parameter
consistent- larger sample makes estimator more accurate
efficient- estimator has the smallest standard deviation
calculated from a large number of random samples that contain the value of the
population parameter
confidence level
the area outside of the region of confidence
significance level, denoted by a
in t statistic a/2 gives the
area in one tail (column of t-table)
in t statistic n-1 gives the
degrees of freedom (row of t-table)
the right term in a confidence interval estimate
margin of error
