## Transcribed Text

1) Descriptive statistics focuses on summarizing data while inferential
statistics deals with the selection and use of sample data to produce
information about the larger population from which the sample was
selected.
a. True b. False
2) Time series data are data collected at, or representing, multiple time
periods.
a. True b. False
3) The mean identifies the center of the data separating it 50/50
a. True b. False
4) The most frequently occurring value of a data set is called the median.
a. True b. False
5) A survey collects only sample data.
a. True b. False
6) When calculating the p
th percentile, if the index i IS an integer then take the
average of the data values in the i – 1 and i + 1 positions.
a. True b. False
7) The interquartile range measures the middle 68.3% of the values in the data
set.
a. True b. False
8) If a data value has a z-score of -3.05 then it is considered an outlier.
a. True b. False
9) In a state tax form, taxpayers are asked for their marital status and
employment details. The marital status is an example of:
2
a. Quantitative data
b. Qualitative data
c. Qualitative or Quantitative depending if it is entered as text or numbers
d. Ratio data
e. Private data
10) Which variable is usually non-numeric rather than numeric?
a. number of siblings
b. birth weight
c. educational level
d. baking temperature
e. speed limit
11) Where can we find Statistics being used?
a. epidemiology
b. marketing
c. journalism
d. sports
e. all of the above
12) In a sample of 200 employees in a west coast Tech company, 75, or 35%,
self-identified as Hispanic. Based on this result, the company reported that
“about a third of our employees are Hispanics”. This report is an example
of:
a. a sample
b. a population
c. statistical inference
d. descriptive statistics
e. none of the above
13)If the variance of a data set is correctly computed with the formula using n -
1 in the denominator, which of the following is true:
a. the data set is a sample
b. the data set is a population
c. the data set could be either a sample or a population
d. the data set is from a census
e. none of the above
14) Which of the following is an accurate interpretation of the standard
deviation of a population?
3
a. The standard deviation represents the exact average distance of each
observation to the mean.
b. The standard deviation represents the square root of the average squared
distance of each observation to the mean.
c. The standard deviation represents the square root of the sum of the squared
distance of each observation to the mean.
d. The standard deviation represents the average deviation of each observation
from the mean.
e. The standard deviation calculation involves n-1 in the denominator.
15) When looking at the shape of a distribution, which of the following best
describes positive skewness?
a. the distribution is evenly split into two identical halves
b. the distribution has an elongated tail in the right-hand direction
c. the distribution has an elongated tail in the left-hand direction
d. the distribution has a very steep single peak
e. the distribution has two separate peaks with a valley in between
16) Which of the following graphical presentations for depicting quantitative data
has no natural separation between rectangles of adjacent classes:
a. bar chart
b. pie chart
c. histogram
d. box-and-whisker plot
e. scatter diagram
17) The interquartile range is used as a measure of variability to overcome what
difficulty of the range?
a. the sum of the range variances is zero
b. the range is difficult to compute
c. the range is influenced too much by extreme values
d. the range is negative
e. none of the above
18) A coffee shop finds that the correlation between daily high temperature and
daily sales is -0.74. The interpretation of this value is as follows:
a. The value of sales falls approximately $0.74 for each degree that the temperature
increases.
4
b. The slope of the linear relationship between temperature and sales is -0.74; there
is a positive relation between the two.
c. There is a negative association between temperature and sales: as the
temperature falls, sales tend to decrease.
d. There is a negative association between temperature and sales: as the
temperature falls, sales tend to increase.
e. There is a negative association between temperature and sales: as the
temperature falls, sales tend to decrease by $0.74.
19)Studies have shown that the number of fire engines at a fire and the
amount of damage done by the fire are highly and positively correlated.
Which of the following conclusions seems most appropriate?
a. send as few fire engines to a fire as possible.
b. the presence of more fire engines tends to cause more confusion, leading to
greater fire damage.
c. the number of fire engines and the amount of fire damage are both related to a
third factor—the size of the fire—and so are correlated to one another.
d. fires and fire engines have something in common – they are both red.
e. none of the above
20)Which of the following best describes the coefficient of variation?
a. it measures variation as a percentage of the mean.
b. it calculated as the mean divided by the standard deviation.
c. it is not helpful when comparing the dispersion in data sets that have different
means
d. it can only be calculate using population parameters, not sample statistics
e. all of the above
5
The table shows the life expectancy of the G8 countries (Datablog,
Guardian.co.uk, July 8 2009)
21) What is the mean life expectancy of the eight countries?
a. 78.0
b. 80.5
c. 81.0
d. 75.0
e. 860.0
22) What is the median life expectancy of the eight countries?
a. 78.0
b. 80.5
c. 81.0
d. 75.0
e. 860.0
23)What is the mode of life expectancy in the eight countries?
a. 78 years
b. 80 years
c. 81 years
d. 75 years
e. 860 years
24) What is the range of life expectancy in the eight countries?
a. 17 years
b. 25 years
c. 28.25 years
d. 78 years
e. 83 years
Canada 81
China 73
France 81
Germany 80
Italy 81
Japan 83
Russia 66
United Kingdom 79
6
25) Treating the data as a population, what is the mean absolute deviation (MAD) of life
expectancy in the eight countries, in years?
a. 4.25
b. 4.86
c. 5.3
d. 55.0
e. 78
:
26) Treating the data as a population, what is the variance of life expectancy in the eight
countries, in years squared?
a. 5.3
b. 5.7
c. 10.15
d. 28.25
e. 32.3
7
The following chart gives the number of full years served by the first 42
presidents of the United States (up to and including George W. Bush).
27) What is the average number of full years served by the first 42 presidents of the
United States?
a. 4.0 years
b. 4.2 years
c. 4.8 years
d. 5.2 years
e. 6.5 years
28) What is the standard deviation of full years served by the first 42 presidents of the
United States? Remember that this includes all of the presidents.
a. 2.0 years
b. 4.0 years
c. 5.2 years
d. 6.5 years
e. 8.3 years
Full Years Frequency
0 1
1 2
2 2
3 3
4 15
5 2
6 2
7 1
8 13
12 1
8
Below is a table showing the ages of current active users of
FaceTime.com.
Age of
User
Number of
Users
0-20 81.2
20-40 79.5
40-60 84.1
60-80 45.9
80-100 11.4
100-120 0.1
29) Use the table to approximate the mean age of users.
a. 43.75
b. 32.44
c. 35.14
d. 41.22
e. 38.55
30) Use the table to approximate the variance of user ages.
a. 431.27
b. 526.35
c. 367.19
d. 484.23
e. 572.84
31) Use the table to approximate the standard deviation of user ages.
a. 22.9
b. 19.7
c. 12.8
d. 34.6
e. 25.2
9
The table below shows the advertising expenditures in $millions for the
nine largest tech companies during the past year.
Company Advertising
Apple 132.1
Samsung 179.6
HP 234.7
Microsoft 146.5
IBM 144.1
Panasonic 171.0
Toshiba 194.9
Sony 169.6
Dell 169.5
32) Determine the median advertising expenditure.
a. 175.8
b. 181.2
c. 156.4
d. 169.6
e. 190.5
33) Determine the 25th percentile or first quartile value here.
a. 138.6
b. 146.5
c. 122.5
d. 119.0
e. 133.8
34)Determine the 75th percentile or third quartile value here.
a. 183.4
b. 196.1
c. 165.9
d. 187.3
e. 179.6
10
35) Profits (in $millions) for Caldwell-Hewitt’s US Division and European
Division over the past four years are shown below. Judging by the
correlation coefficient
Year US Europe
1 6.9 15.4
2 6.3 14.7
3 7.1 16.1
4 7.4 16.5
a. The correlation is strong and when the US grows, Europe declines
b. The correlation is strong and when the US grows, Europe grows
c. The correlation is weak and when the US grows, Europe declines
d. The correlation is weak and when the US grows, Europe grows
e. The correlation is close to zero US and Europe are close to flat
36) We are betting in a 4-horse race, we know the odds and have
translated the odds to the mean of their winning chance, we also
know the standard deviation of their last 10 races. How would a
rational bettor place his/hers win, place, show (1st, 2nd, 3rd) bet?
a. A, B, C
b. B, C, D
c. C, B, D
d. D, C, A
e. Would not bet on this race
winning
odds chance Std. Dev
Horse A 4|1 20% 45%
Horse B 7|1 14% 20%
Horse C 2|1 33% 40%
Horse D 5|2 29% 50%
11
37) Andrew Costanzo has a stock portfolio that contains 24 shares
of stock A and six shares of stock B. Over the past year, the value of
a share of stock A went up to $3.00 and the value of a share of stock
B fell to $50. Apply a weighted average approach to produce the
current average value per share in Andrew’s portfolio.
a. 15.7
b. 12.4
c. 13.8
d. 21.3
e. 14.9
38) The table below shows the grades for three students, using the
credits as the weights and the grading scale. Rank the students, by
their weighted average grade point, highest to lowest.
a. ABC
b. ACB
c. CAB
d. BAC
e. BCA
Credits Student A Student B Student C
Class 1 4 A- B- A
Class 2 3 A A B
Class 3 3 B+ B B
Class 4 4 B B A
Class 5 3 B A- B+
Grading Scale
A 4.00
A- 3.67
B+ 3.33
B 3.00
B- 2.67
C 2.00

This material may consist of step-by-step explanations on how to solve a problem or examples of proper writing, including the use of citations, references, bibliographies, and formatting. This material is made available for the sole purpose of studying and learning - misuse is strictly forbidden.

1 a. True

2 a. True

3 b. False

4 b. False

5 b. False

6 a. True...