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sampling plan, experimental design
The way a sample is selected is called the _______ or _______.
simple random sampling
_______ is a commonly used sampling plan in which every sample of size n has the same chance of being selected.
simple random sample
If the sample of n = 2 observations is selected so that each of these six samples has the same chance—one out of six or 1/6—of selection, then the resulting sample is called a _______, or just a random sample.
random, simple random sample
If a sample of n elements is selected from a population of N elements using a sampling plan in which each of the possible samples has the same chance of selection, then the sampling is said to be _______ and the resulting sample is a _______.
observational study
The situation described in the example is called an _______ because the data already existed before you decided to observe or describe it.
surveys
Most sample _______, in which information is gathered with a questionnaire, fall into this category.
strata, stratified
When the population consists of two or more subpopulations, called _______, a sampling plan that ensures that each subpopulation is represented in the sample is called a _______ random sample.
cluster
Another form of random sampling is used when the available sampling units are groups of elements, called _______.
clusters
A cluster sample is a simple random sample of _______ from the available clusters in the population.
ordered
Sometimes the population to be sampled is _______, such as an alphabetized list of people with driver's licenses, a list of utility users arranged by service addresses, or a list of customers by account numbers.
1-of-k
A _______ systematic random sample involves the random selection of one of the first k elements in an ordered population, and then the systematic selection of every kth element thereafter.
convenience
_______ sample — a sample that can be easily and simply obtained without random selection.
statistics
When you select a random sample from a population, the numerical descriptive measures you calculate from the sample are called _______.
random variable
These statistics vary or change for each different random sample you select; that is, they are _______.
sampling
The probability distributions for statistics are called _______ distributions.
central limit theorem (CLT)
One important statistical theorem that describes the sampling distribution of statistics that are sums or averages is the _______.
normal
Under rather general conditions, this theorem states that sums and means of random samples of measurements drawn from a population tend to have an approximately _______ distribution
central limit theorem (CLT)
This phenomenon is the result of an important statistical theorem called the _______.
mew(μ), sigma over square root of n
If random samples of n observations are drawn from a nonnormal population with finite mean μ and standard deviation σ, then, when n is large, the sample mean follows a normal distribution with mean _______ and standard deviation _______.
normal, n times mew, square root n times sigma
The Central Limit Theorem can be restated to apply to the sum of the sample measurements Σx i , which, as n becomes large, also has an approximately _______ distribution with mean _______ and standard deviation𝜎 𝑛.
normal
If the sampled population is _______, then the sample mean is normal no matter what the size is
symmetric
When the sampled population is approximately _______, the sampling distribution of )𝑋 is normal for a relatively small n.
skewed
When the sampled population is _______, the sample size n must be larger (at least 30) in order for )𝑋 to be approximately normal.
standard error, error
The standard deviation of a statistic used as an estimator of a population parameter is also called the _______ of the estimator because it refers to the _______ of the estimator.
