Business Stats Exam 3

Ace your homework & exams now with Quizwiz!

The power of a test is

(1-B)

When the sample size is equal to or more than 30, the distribution of the samples; mean will be _______ even though the population distribution may be extremely skewed.

approximately normal

The Central Limit Theorem states that regardless of the shape of the population distribution, the distribution of the samples' mean will be _______, provided that the samples we take are ________.

approximately normal; sufficiently large

In a one-tailed test of hypothesis, the critical point is a point that

divides the area under the sampling distribution of a sample statistic into one rejection and one non rejection region

The probability distribution of a sample statistic is called

the sampling distribution of that statistic

Suppose we know that the mean age of all students at a university is 24 years. The mean age of a random sample of 100 students selected from this university is found to e 23.6 years. The difference 23.6 - 24= -0.4 is called:

the sampling error

A sampling distribution is the probability distribution of

A sample statistic

The sampling distribution is the probability distribution of

A sample statistic

In a two-tailed test of hypothesis, the two critical points:

divide the area under the sampling distribution of a sample statistic into two rejection and one non region

The formula for the standard error of the proportion used in hypothesis testing is the same as that used in interval estimation.

False

The sample mean is an inconsistent estimator of the population mean

False

Given the sample size, the standard error of the mean will be larger,

The larger the standard deviation of the population from which the samples are taken.

The mean of the sampling distribution of the sample mean is....

The mean of the means of all possible samples of the same size taken from the population

The relationship between a parameter and its corresponding statistic can be describes as:

The statistic deals only with the sample, wile the parameter deals with population. The statistic is often a good estimator of the parameter. If the estimator is consistent, as the sample size becomes large, the value of the statistic approaches the value of the parameter.

An estimator is said to be unbiased if the expected value of the statistic is equal to the value of the corresponding parameter.

True

The critical value enables us to identify the rejection region in hypothesis testing

True

The wiser the confidence interval is, the less precise is our estimate of the parameter

True

The error of rejection a true null hypothesis is called _________

Type I error

The error of not rejecting a false null hypothesis is called _______

Type II error

The null hypothesis is a claim:

about a population parameter that is assumed to be true until it is declared false.

the alternative hypothesis is a claim:

about a population parameter that will be true if the null hypothesis is false.

The mean of of the sampling distribution of the sample mean

always equal to the population mean

The sample mean is:

an estimator of the population mean, an unbiased estimator of M, a consistent estimator of p.

The sample proportion is:

an estimator of the population proportion, an unbiased estimator of p, a consistent estimator of p.

The Central Limit Theorem states that when the sample size is sufficiently large, the sampling distribution of the proportion will be ____ with its mean centered at ____ and its standard deviation equal to ____.

approx. normal; p; squareroot: (pq/n)

As the confidence coefficient (CC) increases, the confidence interval...

becomes wider

the sampling distribution of p hat is normal if

boh np > 5 and np > 5

The sampling distribution of the proportion is approximately normal when...

both np > 5 and nq > 5

The significance level, denoted by alpha, is the probability of

committing a Type I error

If an estimator tends to approach the value of the population parameter as the sample size increases, the estimator is said to be

consistent

As sample size increases, the probability that the mean of a sample will be vary far away from the mean of the population will:

decrease

When n increases, the standard error of the mean _______

decreases

With a fixed sample size, as Type I error increases, Type II error

decreases

In determining the sample size needed to estimate a parameter, a researcher need to

know the confidence coefficient, know the maximum error of estimation desired, have an idea about the standard deviation

The sample size needed to estimate a parameter is

larger the larger confidence coefficient is, larger the larger the variance is, larger the more precisely you want to be able to estimate the parameter.

Non sampling errors are the errors

made while collecting, recording, and tabulating data

The standard error of the mean...

measures the amount of variation in the sampling distribution

As n increases, the sample mean will become _____ around the population mean.

more clustered

The further away the mean of our sample is from the hypothesis population mean, the _______ we are to reject the null hypothesis.

more likely

The standard deviation of the sampling distribution of the sample mean decreases when

n increases

The mean of the sampling distribution of p hat is always equal to

p

The value of Beta gives the

probability of committing a Type II error

The standard error of the mean is _____ the standard deviation of the population from which the samples are taken.

smaller than

A sampling error is

the difference between the value of a sample statistic based on a random sample and the value of the corresponding population parameter.

The probability of rejecting a correct null hypothesis is ____ which is represented by the symbol _______

the level of significance of a test; a

The mean of the sampling distribution of x bar is always equal to...

the mean

Suppose we know that the mean weekly earning of all employees of a company are $822. The mean weekly earning of a random sample if 25 employees selected form theis company is found to be $837. The difference 837 - 822 = 15 is called:

the non-sampling error

A two-tailed test is a test with

two rejection regions

By rejecting the null hypothesis, are you stating that the alternative hypothesis is true?

yes (proof by contradiction)


Related study sets

15. Resting Membrane Potential WEAK

View Set

CAE Sentence Transformation Part 3

View Set

Unit 1 Review: Ch 1 & 2 Perry Maternal Child

View Set

Part III Neural Communication-Synapse, CH. 7

View Set

Forensic Science, Chapter #2, Securing and Searching the Crime Scene

View Set

Chapter 33: Drugs Affecting Hematopoiesis

View Set

Periodic Functions (Period and Amplitude)

View Set