STAT Chp 7

18

A simple random sample of 5 observations from a population containing 400 elements was taken, and the following values were obtained. 12 18 19 20 21 A point estimate of the population mean is _____.

18

Exhibit 7-3 The following information was collected from a simple random sample of a population. 16 19 18 17 20 18 Refer to Exhibit 7-3. The point estimate of the mean of the population is _____.

a parameter

Exhibit 7-4 A random sample of 121 bottles of cologne showed an average content of 4 ounces. It is known that the standard deviation of the contents (i.e., of the population) is 0.22 ounces. Refer to Exhibit 7-4. In this problem, the .22 is _____. a. a parameter b. a statistic c. the standard error of the mean d. the average content of colognes in the long run

.0200

Exhibit 7-4 A random sample of 121 bottles of cologne showed an average content of 4 ounces. It is known that the standard deviation of the contents (i.e., of the population) is 0.22 ounces. Refer to Exhibit 7-4. The standard error of the mean equals _____.

b.whenever the sample size is more than 5% of the population size

a finite population correction factor is needed in computing the standard deviation of the sampling distribution of the sample means a.whenever the population is infinite b.whenever the sample size is more than 5% of the population size c.whenever the sample size is less than 5% of the population size d.the correction factor is not necessary if the population has a normal distribution

a statistic

a numerical measure from a sample, such as a sample mean, is known as ____ a.a statistic b.a parameter c.the mean deviation d.the central limit theorem

b. 56

a population consists of 8 items. the # of different simple random samples of size 3 (without replacement) that can be selected from this population is _____ a. 24 b. 56 c. 512 d. 128

.1359

a population has a mean of 180 and a standard deviation of 24. a sample of 64 observations will be taken. the probability that the mean from that sample will be between 183 and 186 is _____

b. .0495

a population has a mean of 53 and a standard deviation of 21. a sample of 49 observations will be taken. the probability that the sample mean will be greater than 57.95 is _____ a.0 b. .0495 c. .4505 d. none

c..5 and .047

a population of size 1,000 has a proportion of .5. therefore, the proportion and the standard deviation of the sample proportion for samples of size 100 are______ a.500 and .047 b.500 and .050 c..5 and .047 d..5 and .050

d.sampling distribution

a probability distribution for all possible values of a sample statistic is known as a ______ a.sample statistic b.parameter c.simple random sample d.sampling distribution

c.systematic sampling

a probability sampling method in which we randomly select on of the first k elements and then select kth element thereafter is _____ a.stratified random sampling b.cluster sampling c.systematic sampling d.convenience sampling

.0400

a random sample of 150 people was taken form a very large population. ninety of the people in the sample were females. the standard error of the proportion of females is _____

.0200

a random sample of size 525 are taken from a process whose population proportion is .3. the standard deviation of the sample proportions is ____

d.normal if the population is normally distributed

a sample of 24 observations is taken from a population that has 150 elements. the sampling distribution of x is _____ a.approximately normal because is always approximately normally distributed b.approximately normal because the sample size is large in comparison to the population size c.approximately normal because of the central limit theorem d.normal if the population is normally distributed

approximately normal if np ≥ 5 and n(1 - p) ≥ 5

a sample of 25 observations is taken from a process. the sampling distribution of p is ____ a. not normal since n<30 b. approximately normal because is always normally distributed c. approximately normal if np ≥ 5 and n(1 - p) ≥ 5 d.approximately normal if np > 30 and n(1 - p) > 30

.0668

a sample of 400 observations will be taken from a process. the population proportion equals .8. the probability that the sample proportion will be greater than .83 is _____

.0819

a sample of 51 observations will be taken from a process. the population proportion equals .85. the probability that the sample proportion will be between .9115 and .946 is _____

c.of the central limit theorem

a sample of 92 observations is taken from a process. the sampling distribution of x is approximately normal because _____ a.x is always approximately normally distributed b.the sample size if small in comparison to the population size c.of the central limit theorem d.none of the answers is correct

a.point estimator

a sample statistic, such as x, that estimates the value of the corresponding population parameter is known as a _____ a.point estimator b.parameter c.population parameter d.parameter and a population parameter

point estimate

a simple random sample for 28 observations was taken from a large population. the sample mean equaled 50. 50 is a _____

15

a simple random sample of 64 observations was taken from a large population. the population standard deviation is 120. the sample mean was determined to be 320. the standard error of the mean is _____

n has the same probability of being selected

a simple random sample of size n from a finite population of size N is a sample selected such that each possible sample of size ____

d.point estimate

a single numerical value used as an estimate of a population parameter is known as a _____ a.parameter b.population parameter c.parameter or a population parameter d.point estimate

b.sample

a subset of a population selected to represent the population is a _____ a.subset b.sample c.small population d.none of the answers is correct

d.np ≥ 5 and n(1 − p) ≥ 5

as a general rule, the sampling distribution of the sample proportions can be approximated by a normal probability distribution whenever _____ a.np ≥ 5 b.n(1 − p) ≥ 5 c.n ≥ 30 d.np ≥ 5 and n(1 − p) ≥ 5

d. normal probability distribution

as the sample size become larger, the sampling distribution of the sample mean approaches a ______ a.binomial distribution b.poisson distribution c. hypergeometric distribution d. normal probability distribution

d.normal probability distribution

as the sample size becomes larger, the sampling distribution of the sample mean approaches a _____ a.binomial distribution b.poisson distribution c.hypergeometric distribution d.normal probability distribution

standard error of the mean decreases

as the sample size increases, the _____ a.standard deviation of the population decreases b.population mean increases c.standard error of the mean decreases d.standard error of the mean increases

a probability sampling method

cluster sampling is ______ a.a nonprobaility sampling method b.the same as convenience sampling c.a probability sampling method d.none of the answers is correct

c.a nonprobaility sampling technique

convenience sampling is an example of ____ a.probabilistic sampling b.stratifed sampling technique c.a nonprobaility sampling technique d.cluster sampling

a random variable

if we consider the simple random sampling process as an experiment, the sample mean is ____

c.n/N ≤ 0.05

in computing the standard error of the mean, the finite population correction factor is not used when _____ a.n/N > 0.05 b.N/n ≤ 0.05 c.n/N ≤ 0.05 d.n ≥ 30

sample are used to estimate the population parameter

in point estimation, data from the _____ a. population are used to estimate the population parameter b.samples are used to estimate the population parameter c.sample are used to estimate the sample statistic d. none of the answers

b.infinite population

it is impossible to construct a frame for a(n) a.finite population b.infinte population c.target population d.sampled population

a. .2 and .04

random sample of size 100 are taken from a process whose population proportion is .2. the mean and standard deviation of the distribution of sample proportions are ____ a. .2 and .04 b..2 and .2 c.20 and .04 d.none

c.180 and 1.74

random samples of size 49 are taken from a population that has 200 elements, a mean of 180, and a variance of 196. the distribution of the population is unknown. the mean and the standard error of the distribution of sample means are_____ a.180 and 24.39 b.180 and 28 c.180 and 1.74 d.180 and 2

c.the population is first divided into groups, and then random samples are drawn from each group

stratified random sampling is a method of selecting a sample in which _____ a.the sample is first divided into groups, and then random samples are taken from each group b.various strata are selected from the sample c.the population is first divided into groups, and then random samples are drawn from each group d.none of the answers is correct

10

the # of random samples (without replacement) of size 3 that can be drawn from a population of size 5 is ____

10

the # of random samples of size 3 that can be drawn from a population of size 5 is ____

c.central limit theorem

the basis for using a normal probability distribution to approximate the sampling distribution of x and p is _____ a. cebyshev's theorem b.the empirical rule c.the central limit theorem d.bayes theorm

d.μ

the expected value of the random variable x is _____ a.σ b.the standard error c.the sample size d.μ

a.central limit theorem

the fact that the sampling distribution of the sample mean can be approximated by a normal probability distribution whenever the sample size is large is based on the _____ a.central limit theorem b.fact that there are tables of areas for the normal distribution c.assumption that the population has a normal distribution d.normal probability theorem

infinite

the population being studied is usually considered _____ if it involves an ongoing process that makes listing or counting every element in the population impossible

c.target population

the population we want to make inferences about is the ____ a.sampled population b.frame c.target population d.finite population

sampling distribution of the sample mean

the probability of all possible values of the sample mean is called the ____ a.central probability distribution b.sampling distribution of the sample mean c.random variation d. standard error

b.population based upon info contained in the sample

the purpose of statistical inference is to provide info about the _____ a.sample based upon info contains din the population b.population based upon info contained in the sample c.population based upon info contained in the population d.mean of the sample based upon the mean of the population

μ

the sample mean is the point estimator of _____ a.μ b.σ c.x d.p

σ

the sample statistic "s" is the point estimator of _____

a.is the probability distribution showing all possible values of the sample mean

the sampling distribution of the sample mean____ a.is the probability distribution showing all possible values of sample mean b.is used as a point estimator of the population mean u c.is an unbiased estimator d.shows the distribution of all possible values of u

d.a population

the set of all elements of interest in a study is _____ a.set notation b.a set of interest c.a sample d.a population

a.standard error

the standard deviation of a point estimator is the _____ a.standard error b.sample statistic c.point estimate d.sampling error

b.standard error of the mean

the standard deviation of all possible x values is called the ____ a.standard error of the proportion b.standard error of the mean c.mean deviation d.central variation

d.standard error of the proportion

the standard deviation of p is referred to as the ____ a.standard proportion b.sample proportion c.average proportion d.standard error of the proportion

b.standard error of the mean

the standard deviation of x is referred to as the ____ a.standard x b.standard error of the mean c.sample standard mean d.sample mean deviation

15

there are 6 children in a family. the # of children defines a population. the # of simple random samples of size 2 (without replacement) that are possible equals ______

for any sample size

when the population has a normal distribution, the sampling distribution of x is normally distributed ____ a.for any sample size b.for any sample size of 30 or more c.for any sample size of 50 or more d.for any sample from a finite population

c. s

which of the following is a point estimator? a.σ b.4 c.s d.x

d. judgement sampling

which of the following is an example of a nonprobaility sampling technique? a.simple random sampling b.stratified random sampling c.cluster sampling d.judgement sampling

d.convenience sampling

which of the following sampling methods does not lead to probability samples? a.stratified sampling b.cluster sampling c.systematic sampling d.convenience sampling

d.could be any value

Exhibit 7-1 The following data were collected from a simple random sample from a process (an infinite population). 13 15 14 16 12 Refer to Exhibit 7-1. The mean of the population _____. a.is 14 b.is 15 c.is 15.1581 d.could be any value

1.581

Exhibit 7-1 The following data were collected from a simple random sample from a process (an infinite population). 13 15 14 16 12 Refer to Exhibit 7-1. The point estimate of the population standard deviation is _____.

c.75

Exhibit 7-2 Four hundred registered voters were randomly selected and asked whether gun laws should be changed. Three hundred said "yes," and 100 said "no." Refer to Exhibit 7-2. The point estimate of the proportion in the population who will respond "yes" is _____. a.300 b.approximately 300 c..75 d..25