business stats ch 7

Cluster sampling works best

when most of the variation in a population is within groups and not between groups.

A _____ is representative of population data

census

According to the CLT, as the population proportion deviates from p =___ , we need a larger sample size for the approximation.

.5

A parameter is a ____, although its value may be unknown.

Blank 1: constant

PP formula

X/n

If the population from which the sample is drawn is normally distributed, then the sampling distribution of the sample mean is

always normally distributed.

In general, the variability between sample means is ____ ____ the variability between observations.

less than

Nonresponse bias occurs when

those responding to a survey or poll differ systematically from the non-respondents.

A population has a mean of 100 and a standard deviation of 10. A random sample of 25 is selected. The expected value of XX is equal to ______

100 The expected value of XX is equal to the population mean.

expected value

p

Variance formula

p(1-p)/n

a PP represents the sample _____

proportion

PP is a ____ variable

random

We use Excel's ______ function to generate random integers within some interval.

Blank 1: RANDBETWEEN

A _____ captures a small number of people who fit a particular category.

Blank 1: survey

As a general guideline, the normal distribution approximation can be used to describe the sampling distribution of the sample mean when

n>30

If the shape of the population from which a simple random sample is drawn is normal, then the shape of the sampling distribution of XX is .

normal

Bias can occur in sampling. Bias refers to _______.

the tendency of a sample statistic to systematically over- or underestimate a population parameter

Stratified sampling is preferred to cluster sampling when the objective is

to increase precision.

standard error

square root of variance

Which of the following is true about a sample statistic such as the sample mean or sample proportion?

A sample statistic is a random variable.

The central limit theorem states that, for any distribution, as n gets larger, the sampling distribution of the sample mean becomes

C.is closer to a normal distribution [REASON] for the sample size n ≥ 30, it stays theat any data should follows the normal distrubution

How does the variance of the sample mean compare to the variance of the population?

It is smaller and therefore suggests that averages have less variation than individual observations.

When the information from a sample is not typical of information in the population in a systematic way, we say that _____ has occurred.

bias

_____ sampling is preferred when the objective is to reduce costs.

cluster

Statistics are used to estimate population parameters, particularly when it is impossible or too expensive to poll an entire population. A particular value of a statistic is referred to as a(n) ______.

estimate

If X is normally distributed with expected value μ and standard deviation σ, then XX is normally distributed with

expected value μ and standard deviation σ/√nn.

We use R's ______ function to generate random integers within some interval.

sample

formula for standard error

standard deviation / square root of sample size

The expected value of PP is the proportion of ____ in the population

successes

A ____ is representative of sample data

survey

The standard deviation of XX is calculated as

the positive square root of the variance of XX.

PP is an ____ estimator of _____

unbiased

The sample mean is an ____ estimator of the population mean.

unbiased

Which of the following is considered an estimator?

XX

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 _____ _____

inferential stats

One way to battle social-desirability bias is to use _____ surveys.

online

The expected value of the sample mean equals the mean,.

population

____ _____ bias refers to a systematic difference between a group's "socially acceptable" responses to a survey or poll and this group's ultimate choice.

Blank 1: Social Blank 2: desirability

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____ ____ ____ .

Blank 1: central or C Blank 2: limit or L Blank 3: theorem or T

A PP is an ___ of pp

Blank 1: estimator

When a sample statistic is used to make inferences about a population parameter, it is referred to as an ____

Blank 1: estimator

(line above)X's _____ ______ is simply the probability distribution derived from all possible samples of a given size from the population.

Blank 1: sampling Blank 2: distribution

If a population is known to be normally distributed, what can be said of the sampling distribution of the sample mean drawn from this population?

For any sample size n, the sampling distribution of the sample mean is normally distributed.

The sample size required to approximate the normal distribution depends on

how much the population varies from normality.