ISDS CH. 7 Questions
Estimate
A particular value of an estimator
A subset of the population
A sample is
Bias
If a sample statistic consistently over or under estimates a population parameter, then there is _______________.
Statistic
Random Variable
0.25
Random samples of size 400 are taken from a population whose population proportion is 0.25. The expected value of the sample proportion is ________.
Inferential Statistics
The branch of statistics that uses sample statistics to estimate a population parameter or test a hypothesis about such a parameter is BEST referred to as ______________.
Approaches a normal distribution
The central limit theorem states that as n gets larger, the sampling distribution of the sample proportion
Proportion of successes in the population
The expected value of P^- is the
u~
The expected value of X^- is equal to _____.
u~
The expected value of the sample mean
Those responding to a survey or poll differ systematically from the non-respondents
Nonresponse bias occurs when
(o^2)/n
The variance of the sample mean
Sample
A population consists of all items of interest in a statistical problem, whereas a _______________ is a subset of the population.
Representative of the population from which it was chosen
A simple random sample is a sample of observations that is
Central Limit Theorem
A theorem that allows us to use the normal probability distribution to approximate the sampling distribution of the sample mean whenever the sample size is large is known as the
n >_ 30
As a general guideline, the normal distribution approximation can be used to describe the sampling distribution of the sample mean when
Parameter
Constant
Normal
If the shape of the population from which a simple random sample is drawn is normal, then the shape of the sampling distribution of X^- is
Stratified Random Sampling
In __________, the population is divided up into mutually exclusive and collective exhaustive groups called strata. The sample consists of randomly-selected elements from each stratum.
To increase precision
Stratified sampling is preferred to cluster sampling when the objective is
0.625 10/ (square root of 256) = 0.625
The population has a mean of 50 and a standard deviation of 10. A random sample of 256 is selected. The standard error of X^- is equal to ________.
(o~)/ (square root of n)
The standard deviation of the sample mean
Estimator
When a sample statistic is used to make inferences about a population parameter, it is referred to as a
The sample is not representative of the population we are trying to describe.
Which of these is a characteristic of a "bad" sample?
Sampling distribution of X^-
The probability distribution of the sample mean is commonly referred to as the _____________.