new quiz 7 Flashcards

1
Q

the way a sample is selected is called the ___________or ____________

A

SAMPLING PLAN, EXPERIMENTAL DESIGN

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

a commonly used sampling plan in which every sample of size n has the same chance of being selected.

A

Simple Random Sampling

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

A simple random sample can also be called a _____

A

random sample

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

when the data already exists and you are just picking the random data for sample

A

observational study

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Most sample_____, in which info is gathered in a questionnaire, fall into this category, obervational study

A

surveys

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

when population consists of 2 or more subpopulations, called ______, a sampling plan that ensures that each subpopulations is represented in the sample is called a ________ random sample

A

strata, stratified

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Stratified random sampling involves selecting a simple random sample from each of a given # of subpops. or strata

A

true

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

A cluster sample is a simple random sample of clusters from the available _____ in the populations

A

clusters

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Sometimes the population to be sampled is _____ such as an alphabetical list of people with driver’s license, then we can use a _________ random sample

A

ordered, systematic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

A ________ systematic randon 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 after that

A

1 of K

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

a sample that can be easily and simply obtained without random selection

A

convenience sample

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

a convenience sample is non-random and can not be used for making inferences

A

true

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

when you select a random sample, the numerical descriptive measure you calculated from the sample are called…

A

statistics`

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

These statistics vary or change from sample to sample, that is they are _______

A

random variables

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

The probability distribution for statistics are called _______ distributions

A

sampling

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

One important statistical theorem that describes the sampling distribution of statistics that are sums of averages is…

A

central limit theorem

17
Q

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

A

normal

18
Q

The spread of the distribution is slowly decreasing as the sample size n increases (true or false)

A

trueeeee

19
Q

CLT- if random samples of n observations are drawn from a non-normal population with finite mean and standard deviation, then , when n is large, the sample mean follows a normal distribution with mean ____ and standard deviation

A

ϻ, σ/√(n)

20
Q

The CLT can be restated to apply to the sum of the sample measurements which as n becomes large, also has an approximate _______ distribution with mean _________ and standard deviation ______

A

normal, n x ϻ, √(n) x σ

21
Q

the standard deviation of a statistic used as an estimator of a population parameter is also called _______ of the estimator (SE), because it refers to the _______ of the estimator

A

standard error, error

22
Q

SE( sample mean)=

A

σ/√(n)

23
Q

estimating or predicting the value of the parameter

A

estimation

24
Q

making a decision about the value of a parameter based on a preconceived idea about what the value might be

A

hypothesis test

25
Q

an ______ is a rule usually expressed as a formula that tells us how to calculate an estimate based on info in a sample

A

estimator

26
Q

a single # is calculated to estimate population parameter

A

point estimator

27
Q

2 numbers are calculated to form an interval within which the parameter is expected to lie withing

A

interval estimator

28
Q

a point estimator is said to be ____ if the mean of its distribution is the true value of the parameter being estimated, otherwise, the estimator is said to be ____

A

unbiased, biased

29
Q

the _____ ( as measured by the variance) of the estimator’s sampling distribution should be as small as possible

A

spread ( better if spread is more concentrated around true value)

30
Q

The distance between an estimate and the true value of the parameter is called the ______ of estimation

A

error

31
Q

the probability that the true value falls into interval is called the ________. (1- α) x 100%

A

confidence

32
Q

If the sample size is large enough, then CLT applies so we can work with ________ distributions

A

normal

33
Q

1-α is the probability that the interval covers the true value. The smaller the α is, the _____ interval is

A

wider

34
Q

if n increases, the interval is getting _____. This is because large n means more information, therefore less uncertainty

A

narrower