CUNY DATA205 Exam 1 Latest 2019 JULY Question # 00603539 Subject: Education Due on: 08/09/2019 Posted On: 08/09/2019 08:27 AM Tutorials: 1 Rating: 4.8/5

DATA205 Introductory Analytics (QC)

Exam 1

Question 1A
discrete variable cannot be

Answers:

a.
subdivided.

b.
multiplied.

c. added.

d.
observed.

Question 2A
researcher has numbered all 50 states from 1 to 50 and has calculated a mean of
17.43 for the variable “state of birth.”

Answers:

a. Since
the variable is ordinal, we should treat the value of the mean with great
caution.

b. Since the variable is nominal, the mean
makes no sense.

c. Since
this variable is discrete, the mean should not be computed.

d. The
variable is interval-ratio and the mean is an appropriate and useful statistic
in this case.

Question 3A
theory differs from an hypothesis in that it is more

Answers:

a.
testable.

b. general.

c.
concrete.

d.
specific.

Question
4According to the “Wheel of Science,” research projects begin

Answers:

a. with
data.

b. at any stage on the Wheel.

c. with an
hypothesis.

d. with
theory.

Question
5Addition and subtraction are completely justified only when variables are

Answers:

a.
discrete.

b. continuous.

c. ordinal.

d. interval-ratio.

Question
6An hypothesis states, in part, that “income increases as education
increases”. In this statement, income is

Answers:

a. the
hypothetical variable.

b. the
independent variable.

c. the dependent variable.

d. the
secondary variable.

Question
7Choose the nominal level variable below:

Answers:

a. size of
family unit

b. speed of
travel of a jet

c. eye color of students in statistics class

d. your
weight

Question
8In social research the purpose of statistics is to

Answers:

a. prove
that the research theory is correct.

b. validate
the research project design.

c. manipulate and analyze data.

d. ensure
acceptance by the scientific community.

Question
9The data reduction process of descriptive statistics

Selected
Answer:

a. allows a
few meaningful numbers to summarize a large amount of data.

b. is
rarely used.

c.
eliminates incorrect data.

d. simply
lists all available information in order.

Question 10
Which of the following is a discrete variable?

Answers:

a. Miles
per gallon

b. Height

c. Number of children

d. Age

Question 11
Without statistics, _____________ research would be impossible.

Answers:

a.
meaningful

b.
qualitative

c.
important

d.
quantitative

Question
12A city of 1567 people had 34 auto thefts last year. The auto theft rate for
this city

Answers:

a. is
(34/1567) x 100,000.

b. is
(100,000 x 1567)/34.

c. is
falling.

d. cannot
be determined from the information given.

Question
13A researcher wants to visually display the U.S. divorce rate (a continuous,
interval-ratio level variable) for the last 50 years. An appropriate format
would be

Answers:

a. a line
chart or histogram.

b. only a
histogram.

c. a pie
chart.

d. none of
the above. Data in the form of rate should never be displayed in a chart or
graph.

Question
14For a single variable measured at the nominal level, an appropriate graph
would be a

Answers:

a.
bivariate table

b.
frequency polygon.

c.
histogram.

d. pie
chart.

Question
15Frequency distributions may be compiled for variables measured at which
level?

Answers:

a. Nominal

b. Ordinal

c.
Interval-ratio

d. All of
the above

Question
16Pie charts show the frequency distribution of

Answers:

a. one
variable.

b. two
variables.

c. three or
more variables.

d. Any of
the above

Question 17The
sum of the proportions for all categories of a variable will be

Answers:

a. 0.10

b. 1.00

c. 10.00

d. 100.00

Question
18To be converted to a percentage, the proportion must be multiplied by

Answers:

a. 10.

b. 100.

c. 1000.

d. Any of
the above

Question
19When working with a very small number of cases, it is usually preferable to
report

Answers:

a.
fractions.

b. actual
frequencies.

c.
proportions.

d.
percentages.

Question
20Which of the following is an impossible value for a percentage?

Answers:

a. 0.0%

b. 110.00%

c. 0.05%

d.
47.458923%

Question
21A researcher is preparing a report and wants to select a measure of central
tendency that shows the most common score in a particular distribution. Which
statistic should she select?

Answers:

a. Mode

b. Median

c. Mean

d. None of
the above

Question
22An instructor is preparing a report showing mid-semester grades and notes
that the mean, median, and mode are all exactly 76.00. What can she conclude?

Answers:

a. The
distribution of grades is unskewed.

b. There is
a negative skew in the distribution (a few students have very low grades.)

c. There is
a positive skew in the distribution (a few students have very high grades.)

d. All of
the above

Question
23As a measure of central tendency, the mode can be used with?

Answers:

a.
?interval-ratio data.

b. ?all of these choices are correct.

c. ?ordinal
data.

d. ?nominal
data.

Question
24For ordinal level variables, the most appropriate measure of central tendency
is generally

Answers:

a. the
mode.

b. the median.

c. the
mean.

d. None of
the above

Question
25If a distribution of test scores has a mean of 70 and a median of 80, the
distribution has

Answers:

a. a
positive skew.

b. a mode
of 75.

c. a few
very high scores.

d. a negative skew.

Question
26If you changed ONLY the highest score in a distribution of 5 scores, which of
the following measure of central tendency would be affected?

Answers:

a. The mean

b. The
median

c. The mode

d. All of
the above

Question
27The expression ?(Xi) directs us to find the

Answers:

a. average
of the scores.

b. median.

c. middle
score.

d. sum of the scores.

Question
28The three commonly used measures of central tendency (mode, median, and mean)

Answers:

a. define
“typical” or “average” in different ways and will usually
have different values.

b.will
always fall in the same order: the mean will have the lowest value, the median
will always be in the middle and the mode will have the highest value.

c. will
always have the same value.

d. will
always fall in the same order: the mean will have the highest value, followed
by the median and the mode.

Question
29Which measure of central tendency is affected by every score in the
distribution?

Answers:

a. The mean

b. The
median

c. The mode

d. All of
the above

Question
30Which of the following correctly matches the level of measurement of a
variable with the preferred measure of central tendency?

Answers:

a. ordinal
… mode

b. ordinal
… median

c.
interval-ratio … mode

d. nominal
… mean

Question
31An advantage of the interquartile range (Q) over the range (R) is that it

Answers:

a. includes
the most extreme scores.

b. is based on only the middle 50% of the
scores.

c. can be
used for nominal level variables.

d. ignores
the first and third quartiles.

Question
32As a distribution of scores becomes more variable, the value of the standard
deviation

Answers:

a.
decreases.

b. increases.

c. becomes
unpredictable.

d. stays
the same.

Question
33If a distribution of scores has a mean of 30 and a range of 0

Answers:

a. the
quartile deviation (Q) is 10.

b. there is no dispersion in the distribution.

c. the
standard deviation is 1.

d. the
variance is 30.

Question
34If a test score lies at the first quartile, it is

Answers:

a. the same
as the median.

b. higher
than 75% of the scores.

c. higher than
25% of the scores.

d. the same
as the mode.

Question 35
If male and female college students have the same mean GPA but the standard
deviation for females is much larger, you may conclude that

Answers:

a. median
GPAs for both groups would be the same.

b. there is
more variability among female students with respect to GPA.

c. males
are smarter than females.

d. modal
GPAs for both groups would be the same.

Question 36
Measures of dispersion provide information about the

Answers:

a. adequacy
of the selection criteria for the sample.

b. variety within the distribution of scores.

c. typical
or most common score.

d. size of
the sample.

Question 37
One problem with the range (R) as a measure of dispersion is that it

Answers:

a. ignores
the most extreme scores.

b. is very
difficult to calculate.

c. can be
used only for nominal level variables.

d. is based on only the most extreme scores.

Question 38
The expression ? instructs us to

Answers:

a. sum the
scores and then subtract the mean.

b. sum the
scores.

c. subtract the mean from each score and add
up the deviations.

d. subtract
every “ith” score from the mean.

Question 39
The lower limit for the standard deviation is 0; the upper limit is

Answers:

a. the
score of the median.

b. a function
of the number of cases.

c. undefined;
there is no upper limit.

d. the
score of the mean.

Question 40
The second quartile (Q2) is equal in value to

Answers:

a. the
range.

b. the
mode.

c. the
mean.

d. the
median.

Question 41What
is the difference between a population and a sample?

Question 42
Below are some items from a survey. For each item, identify the level of
measurement and whether the variable will be discrete or continuous.

a. In what
region of the country were you born?

__ South

__
Northeast

__ Midwest

__ Far West

__ Other

__ Born out
of Country

b. How many
siblings do you have? ___

c. How
satisfied are you with the quality of instruction at this institution?

__ Very
satisfied

__
Satisfied

__
Dissatisfied

__ Very
Dissatisfied

d. How many
miles per gallon does your car average?_____

e. People
convicted of first degree murder should be executed.

__ Strongly
Agree

__ Agree

__ Neither
Agree nor Disagree

__ Disagree

__ Strongly
Disagree

Question 43
In 2005, a study in Smalltown USA reported a crime rate of 204 crimes for every
100,000 residents. A recent report from Smalltown USA’s local newspaper
indicates the crime rate in 2015 was 81 crimes per 10,000 residents.

The mayor
wants to hold a press conference to publicly celebrate the accomplishments of
the police force over the last 10+ years.
Would you agree with the mayor’s assertion that the city is safer now
than it was 10 years ago?

BRIEFLY
explain why or why not. (HINT: no extra
calculations needed to answer this problem)

Question 44
Below is a boxplot for data gathered on Infant Mortality Rates from 70
different countries around the world

Based on
the provided boxplot, what can you say about the distribution of these data?

Question 45
You are the Dean of students at a college and the President has asked for some
information about how the student body has changed over the years. You have
collected the following information regarding the number of students in various
categories for two different graduating classes:

CHARACTERISTICS
OF TWO GRADUATING CLASSES

1990 2010

Total in
class 345 687

Females 178 301

Married 48 117

Humanities
Majors 115 258

Going to
Graduate School 78 159

Attended
Commencement 99 458

Finished in
4 years 269 325

Received
financial aid 159 369

What will you
say to the president when she asks:

a. What
percentage of the glass was going to graduate school in 2010? ______

b .Has this
percentage gone up or down since 1990 and by how much? (Hint: Compute the
percentage change to measure the amount of change between the two times)_____

c. What
proportion of the class majored in the humanities in 1990?________ 2010?_______

Question 46
The frequency distribution below displays the distribution of age for a sample
drawn from a community. Finish the table by completing the columns for
percentages, and cumulative percentages.

AGE

Class
Intervals Frequency Percentage Cumulative

Percentage

10 – 19 9

20 – 29 17

30 – 39 45

40 – 49 56

50 – 60 23

TOTALS

Question
47 Some information about auto theft
rates (number of auto thefts per 100,000 population) for a sample of 178 cities
in two different years is summarized below. Express this statistical
information in words. What changes were there in the overall shape of the distribution
of this variable? In central tendency? In dispersion?

1990 2010

Mean 150.32 125.17

Median 117.17 123.01

Standard
Deviation 12.23 7.01