Complete Short Stats Quizzes

Anonymous
timer Asked: Nov 1st, 2018
account_balance_wallet $10

Question description

COMPLETE EACH QUIZ ON SEPARATE WORD DOCUMENT

CHOOSE THE CORRECT MULTIPLE CHOICE ANSWER

QUIZ 3:

QUESTION 1

1.

A numerical description of the outcome of an experiment is called a

descriptive statistic

probability function

variance

random variable

5 points

QUESTION 2

1.

A random variable that can assume only a finite number of values is referred to as a(n)

infinite sequence

finite sequence

discrete random variable

discrete probability function

5 points

QUESTION 3

1.

A random variable that may take on any value in an interval or collection of intervals is known as a

continuous random variable

discrete random variable

continuous probability function

finite probability function

5 points

QUESTION 4

1.

A description of the distribution of the values of a random variable and their associated probabilities is called a

probability distribution

random variance

random variable

expected value

5 points

QUESTION 5

1.

The expected value for a binomial probability distribution is

E(x) = Pn(1 - n)

E(x) = P(1 - P)

E(x) = nP

E(x) = nP(1 - P)

5 points

QUESTION 6

1.

The variance for the binomial probability distribution is

var(x) = P(1 - P)

var(x) = nP

var(x) = n(1 - P)

var(x) = nP(1 - P)

5 points

QUESTION 7

1.

Which of the following is not a characteristic of an experiment where the binomial probability distribution is applicable?

the experiment has a sequence of n identical trials

exactly two outcomes are possible on each trial

the trials are dependent

the probabilities of the outcomes do not change from one trial to another

5 points

QUESTION 8

1.

The number of electrical outages in a city varies from day to day. Assume that the number of electrical outages (x) in the city has the following probability distribution.
x f(x)
0 0.80
1 0.15
2 0.04
3 0.01

The mean and the standard deviation for the number of electrical outages (respectively) are

2.6 and 5.77

0.26 and 0.577

3 and 0.01

0 and 0.8

5 points

QUESTION 9

1.

The center of a normal curve is

always equal to zero

is the mean of the distribution

cannot be negative

is the standard deviation

5 points

QUESTION 10

1.

A normal distribution with a mean of 0 and a standard deviation of 1 is called

a probability density function

an ordinary normal curve

a standard normal distribution

none of these alternatives is correct

5 points

QUESTION 11

1.

A negative value of Z indicates that

the number of standard deviations of an observation is to the right of the mean

the number of standard deviations of an observation is to the left of the mean

a mistake has been made in computations, since Z cannot be negative

the data has a negative mean

10 points

QUESTION 12

1.

Which of the following is not a characteristic of the normal probability distribution?

The mean, median, and the mode are equal

The mean of the distribution can be negative, zero, or positive

The distribution is symmetrical

The standard deviation must be 1

10 points

QUESTION 13

1.

Z is a standard normal random variable. The P (1.41 ≤ Z ≤ 2.85) equals

0.4978

0.4207

0.9185

0.0771

10 points

QUESTION 14

1.

X is a normally distributed random variable with a mean of 8 and a standard deviation of 4. The probability that X is between 1.48 and 15.56 is

0.0222

0.4190

0.5222

0.9190

10 points

QUESTION 15

1.

Larger values of the standard deviation result in a normal curve that is

shifted to the right

shifted to the left

narrower and more peaked

wider and flatter

QUIZ 4:

QUESTION 1

1.

Parameters are

numerical characteristics of a sample

numerical characteristics of a population

the averages taken from a sample

numerical characteristics of either a sample or a population

10 points

QUESTION 2

1.

Stratified random sampling is a method of selecting a sample in which

the sample is first divided into strata, and then random samples are taken from each stratum

various strata are selected from the sample

the population is first divided into strata, and then random samples are drawn from each stratum

None of these alternatives is correct.

10 points

QUESTION 3

1.

A theorem that allows us to use the normal probability distribution to approximate the sampling distribution of sample means and sample proportions whenever the sample size is large is known as the

approximation theorem

normal probability theorem

central limit theorem

central normality theorem

10 points

QUESTION 4

1.

In point estimation

data from the population is used to estimate the population parameter

data from the sample is used to estimate the population parameter

data from the sample is used to estimate the sample statistic

the mean of the population equals the mean of the sample

10 points

QUESTION 5

1.

The sample statistic s is the point estimator of

μ

σ

x ̅

p ̅

10 points

QUESTION 6

1.

The sample mean is the point estimator of

μ

σ

x ̅

p ̅

10 points

QUESTION 7

1.

The standard deviation of all possible x ̅ values is called the

standard error of proportion

standard error of the mean

mean deviation

central variation

10 points

QUESTION 8

1.

A sample statistic, such as a sample mean, is known as

a statistic

a parameter

the mean deviation

the central limit theorem

10 points

QUESTION 9

1.

The purpose of statistical inference is to provide information about the

sample based upon information contained in the population

population based upon information contained in the sample

population based upon information contained in the population

mean of the sample based upon the mean of the population

10 points

QUESTION 10

1.

Random samples of size 81 are taken from an infinite population whose mean and standard deviation are 200 and 18, respectively. The distribution of the population is unknown. The mean and the standard error of the mean are

200 and 18

81 and 18

9 and 2

200 and 2

QUIZ 5:

QUESTION 1

1.

For the interval estimation of μ when σ is known and the sample is large, the proper distribution to use is

the normal distribution

the t distribution with n degrees of freedom

the t distribution with n + 1 degrees of freedom

the t distribution with n + 2 degrees of freedom

5 points

QUESTION 2

1.

An estimate of a population parameter that provides an interval of values believed to contain the value of the parameter is known as the

confidence level

interval estimate

parameter value

population estimate

5 points

QUESTION 3

1.

The value added and subtracted from a point estimate in order to develop an interval estimate of the population parameter is known as the

confidence level

margin of error

parameter estimate

interval estimate

5 points

QUESTION 4

1.

Whenever the population standard deviation is unknown and the population has a normal or near-normal distribution, which distribution is used in developing an interval estimation?

standard distribution

z distribution

alpha distribution

t distribution

5 points

QUESTION 5

1.

The z value for a 97.8% confidence interval estimation is

2.02

1.96

2.00

2.29

5 points

QUESTION 6

1.

The t value for a 95% confidence interval estimation with 24 degrees of freedom is

1.711

2.064

2.492

2.069

5 points

QUESTION 7

1.

As the sample size increases, the margin of error

increases

decreases

stays the same

increases or decreases depending on the size of the mean

5 points

QUESTION 8

1.

The ability of an interval estimate to contain the value of the population parameter is described by the

confidence level

degrees of freedom

precise value of the population mean μ

degrees of freedom minus 1

5 points

QUESTION 9

1.

In general, higher confidence levels provide

wider confidence intervals

narrower confidence intervals

a smaller standard error

unbiased estimates

5 points

QUESTION 10

1.

An interval estimate is a range of values used to estimate

the shape of the population's distribution

the sampling distribution

a sample statistic

a population parameter




5 points

QUESTION 11

1.

As the number of degrees of freedom for a t distribution increases, the difference between the t distribution and the standard normal distribution

becomes larger

becomes smaller

stays the same

becomes negative

10 points

QUESTION 12

1.

In order to determine an interval for the mean of a population with unknown standard deviation a sample of 61 items is selected. The mean of the sample is determined to be 23. The number of degrees of freedom for reading the t value is

22

23

60

61

10 points

QUESTION 13

1.

After computing a confidence interval, the user believes the results are meaningless because the width of the interval is too large. Which one of the following is the best recommendation?

Increase the level of confidence for the interval.

Decrease the sample size.

Increase the sample size.

Reduce the population variance.

10 points

QUESTION 14

1.

A sample of 225 elements from a population with a standard deviation of 75 is selected. The sample mean is 180.The 95% confidence interval for μ is

105.0 to 225.0

175.0 to 185.0

100.0 to 200.0

170.2 to 189.8

10 points

QUESTION 15

1.

The sample size needed to provide a margin of error of 2 or less with a .95 probability when the population standard deviation equals 11 is

10

11

116

117

Tutor Answer

Robertmariasi
School: Carnegie Mellon University

Hello there,I just wanted to tell you that I finished answering the questions given. In total there were 3 quizzes in ...

flag Report DMCA
Review

Anonymous
Wow this is really good.... didn't expect it. Sweet!!!!

Similar Questions
Hot Questions
Related Tags

Brown University





1271 Tutors

California Institute of Technology




2131 Tutors

Carnegie Mellon University




982 Tutors

Columbia University





1256 Tutors

Dartmouth University





2113 Tutors

Emory University





2279 Tutors

Harvard University





599 Tutors

Massachusetts Institute of Technology



2319 Tutors

New York University





1645 Tutors

Notre Dam University





1911 Tutors

Oklahoma University





2122 Tutors

Pennsylvania State University





932 Tutors

Princeton University





1211 Tutors

Stanford University





983 Tutors

University of California





1282 Tutors

Oxford University





123 Tutors

Yale University





2325 Tutors