Determine whether the sampling method described below appears to be sound or is flawed.

In a survey of 793

subjects, each was asked how often he or she

playedsports.

The survey subjects were internet users who responded to a question that was posted on a news website.

Choose the correct answer below.

A.

It is flawed because it is not statistically significant.

B.

It appears to be sound because the data are not biased in any way.

C.

It is flawed because it is a voluntary response sample.

D.

It is flawed because it is a census.

2. Determine whether the underlined number is a statistic or a parameter.

Inastudyofall3471employeesatacollege,itisfoundthat35%ownacomputer.

Choose the correct statement below.

Parameter

because the value is a numerical measurement describing a characteristic of a

population.

Parameter

because the value is a numerical measurement describing a characteristic of a

sample.

Statistic

because the value is a numerical measurement describing a characteristic of a

population.

Statistic

because the value is a numerical measurement describing a characteristic of a

sample.

3- State whether the data described below are discrete or continuous, and explain why.

Theamountsoftimethatdifferentsurgicalprocedurestakeatahospital

Choose the correct answer below.

A.

The data are

continuous

because

thedatacantakeonany

valueinaninterval.

B.

The data are

continuous

because

thedatacanonlytakeon

specificvalues.

C.

The data are

discrete

because

thedatacanonlytakeon

specificvalues.

D.

The data are

discrete

because

thedatacantakeonany

valueinaninterval.

4- Determine which of the four levels of measurement (nominal, ordinal, interval, ratio) is most appropriate for the data below.

Carlengthsmeasuredinfeet

Choose the correct answer below.

A.

The

interval

level of measurement is most appropriate because the data

canbe

ordered,differences(obtainedbysubtraction)canbefoundandaremeaningful,and

thereisnonaturalstartingpoint.

B.

The

ratio

level of measurement is most appropriate because the data

canbe

ordered,

differences

canbe

found

andare

meaningful,

andthere

isa

natural

starting

zero

point.

C.

The

nominal

level of measurement is most appropriate because the data

cannotbe

ordered.

D.

The

ordinal

level of measurement is most appropriate because the data

canbe

ordered,butdifferences(obtainedbysubtraction)cannotbefoundorare

5-Determine which of the four levels of measurement (nominal, ordinal, interval, ratio) is most appropriate for the data below.

Yearsinwhicharecessionoccurred.

Choose the correct answer below.

A.

The

ordinal

level of measurement is most appropriate because the data

canbe

ordered,butdifferences(obtainedbysubtraction)cannotbefoundorare

meaningless.

B.

The

ratio

level of measurement is most appropriate because the data

canbeordered,

differences(obtainedbysubtraction)canbefoundandaremeaningful,andthereisa

naturalstartingpoint.

C.

The

interval

level of measurement is most appropriate because the data

canbe

ordered,

differences(obtainedbysubtraction)

canbe

found

andare

meaningful,

andthere

isno

natural

starting

zero

point.

D.

The

nominal

level of measurement is most appropriate because the data

cannotbe

ordered.

6- Determine whether the description corresponds to an observational study or an experiment.

Researchisconductedtodetermineifthereisarelationbetweenstomachcancerand

alcoholconsumption.

Does the description correspond to an observational study or an experiment?

Experiment

Observationalstudy

7- Identify the type of sampling used (random, systematic, convenience, stratified, or cluster sampling) in the situation described below.

A researcherselectsevery349thsocialsecuritynumberand

surveys

the

corresponding

person.

Which type of sampling did the

researcher

use?

Systematic

sampling

Cluster

sampling

Convenience

sampling

Random

sampling

Stratified

sampling

8-Identify the type of sampling used (random, systematic, convenience, stratified, or cluster sampling) in the situation described below.

In a poll conducted by a certain research center,

815

adults were called after their telephone numbers were randomly generated by a computer, and

71%

were able to correctly identify the attorneygeneral.

Which type of sampling did the research center use?

Convenience sampling

Random sampling

Stratified sampling

Systematic sampling

Cluster sampling

9-identify the type of sampling used (random, systematic, convenience, stratified, or cluster sampling) in the situation described below.

A

man

is selected by a marketing company to participate in a paid focus group. The company says that the

man

was selected because

he

was

randomly

chosen

from

all

men

in

his

tax

bracket.

Which type of sampling did the marketing company use?

Systematic

sampling

Cluster

sampling

Stratified

sampling

Random

sampling

Convenience

sampling

10-Identify the type of observational study (cross-sectional, retrospective, or prospective) described below.

A research company uses a device to record the viewing habits of about

15,000

households and the data collected

today

will be used to

determinethe

the proportion of households tuned to a particular

educational

program.

Which type of observational study is described in the problem statement?

A

prospective

study

A

cross-sectional

study

A

retrospective

study

11-A frequency table of grades has five classes (A, B, C, D, F) with frequencies of

2,

14,

14,

7,

and

3

respectively. Using percentages, what are the relative frequencies of the five classes?

Complete the table.

Grade	Frequency	Relative frequency
A	2	enter your response here%
B	14	enter your response here%
C	14	enter your response here%
D	7	enter your response here%
F	3	enter your response here%

(Round to two decimal places as needed.)

12-Construct the cumulative frequency distribution for the given data.

Age (years) of Best Actress when award was won	Frequency
20-29	25
30-39	34
40-49	11
50-59	3
60-69	6
70-79	1
80-89	1

.....

Age (years) of Best Actress when award was won	Cumulative Frequency
Less than 30	enter your response here
Less than 40	enter your response here
Less than 50	enter your response here
Less than 60	enter your response here
Less than 70	enter your response here
Less than 80	enter your response here
Less than 90	enter your response here

15- Find the (a) mean, (b) median, (c) mode, and (d) midrange for the data and then (e) answer the given question.

Listed below are foot lengths in inches of randomly selected women in a study of a country's military in 1988. Are the statistics representative of the current population of all women in that country's military?

10.5

8.7

9.4

8.7

9.7

9.8

8.6

9.3

9.0

9.4

9.4

a. Find the mean.

The mean is

enter your response here

inch(es).

(Type an integer or a decimal rounded to two decimal places as needed.)

b. Find the median.

The median is

enter your response here

inch(es).

(Type an integer or a decimal. Do not round.)

c. Find the mode.

Select the correct choice below and, if necessary, fill in the answer box to complete your choice.

A.

The mode(s) is(are)

enter your response here

inch(es).

(Type an integer or a decimal. Do not round. Use a comma to separate answers as needed.)

B.

There is no mode.

d. Find the midrange.

The midrange is

enter your response here

inch(es).

(Type an integer or a decimal. Do not round.)

e. Are the statistics representative of the current population of all women in that country's military? Choose the best answer below.

A.

Since the measurements were made in 1988, they are not necessarily representative of the current population of all women in the country's military.

B.

Since the sample does not include men, the sample should not be considered to be representative of the population.

C.

Since the sample is not a random sample, it should not be considered to be representative of the population.

D.

Since the sample is random and the sample size is greater than 10, the sample can be considered to be representative of the population.

16-One common system for computing a grade point average (GPA) assigns 4 points to an A, 3 points to a B, 2 points to a C, 1 point to a D, and 0 points to an F. What is the GPA of a student who gets an A in a

4-credit

course, a B in each of

three

3-credit

courses, a C in a

3-credit

course, and a D in a

4-credit

course?

The mean grade-point score is

enter your response here.

(Round to the nearest tenth as needed.)

17- The brain volumes

(cm3)

of 20 brains have a mean of

1090.1

cm3

and a standard deviation of

120.8

cm3.

Use the given standard deviation and the range rule of thumb to identify the limits separating values that are significantly low or significantly high. For such data, would a brain volume of

1351.7

cm3

be significantly high?

Significantly low values are

enter your response here

cm3

or lower.

(Type an integer or a decimal. Do not round.)

Significantly high values are

enter your response here

cm3

or higher.

(Type an integer or a decimal. Do not round.)

Is

1351.7

cm3

significantly high?

A.

Yes, because it is between the limits separating values.

B.

No, because it is below the lower limit separating value.

C.

Yes,becauseitisabovetheupperlimitseparatingvalue.

D.

No, because it is above the upper limit separating value.

E.

No,becauseitisbetweenthelimitsseparatingvalues.

F.

Yes,becauseitisbelowthelowerlimitseparatingvalue.

18- Below is the jersey numbers of 11 players randomly selected from a football team. Find the range, variance, and standard deviation for the given sample data. What do the results tell us?

16736413661491720850

Range=enter your response here

(Round to one decimal place as needed.)

Sample standard

deviation=enter your response here

(Round to one decimal place as needed.)

Sample

variance=enter your response here

(Round to one decimal place as needed.)

What do the results tell us?

A.

Jersey numbers on a football team vary much more than expected.

B.

Jersey numbers are nominal data that are just replacements for names, so the resulting statistics are meaningless.

C.

The sample standard deviation is too large in comparison to the range.

D.

Jersey numbers on a football team do not vary as much as expected.

19- Researchers measured the data speeds for a particular smartphone carrier at 50 airports. The highest speed measured was

77.8

Mbps. The complete list of 50 data speeds has a mean of

x=15.98

Mbps and a standard deviation of

s=39.58

Mbps.

a. What is the difference between the carrier's highest data speed and the mean of all 50 data speeds?

b. How many standard deviations is that [the difference found in part (a)]?

c. Convert the carrier's highest data speed to a z score.

d. If we consider data speeds that convert to z scores between

2

and 2 to be neither significantly low nor significantly high, is the carrier's highest data speed significant?

a. The difference is

enter your response here

Mbps.

(Type an integer or a decimal. Do not round.)

b. The difference is

enter your response here

standard deviations.

(Round to two decimal places as needed.)

c. The z score is

z=enter your response here.

(Round to two decimal places as needed.)

d. The carrier's highest data speed is

significant

Significant high

signnificant low

not significantsignificant