BDAN final
Find the z-score for an IQ test score of 92 when the mean is 100 and the standard deviation is 15.
-0.53
The following table shows the Price-to-Earnings ratio for a stereo equipment manufacturing company between 1998 and 2002. Picture Determine the percentage change in the P/E ratios from 1999 to 2000.
-23.97
The following is a partial relative frequency distribution of grades in an introductory statistics course. Picture Find the relative frequency for the B grade.
.37
The average lateness for one of the top airline companies is 10 minutes. The variance of the lateness measure is calculated as 9. An airplane arrived 13 minutes after the stated arrival time. Calculate the z-score for the lateness of this particular airplane.
1
Find the z-score for an IQ test score of 118 when the mean is 100 and the standard deviation is 15.
1.2
A CFO is looking at what percentage of a company's resources are spent on computing. He samples companies in the pharmaceutical industry and develops the following stem-and-leaf graph. Picture What would be the class length used in creating a frequency histogram?
1.4
find the z-score for an IQ test score of 125 when the mean is 100 and the standard deviation is 15
1.67
A local airport keeps track of the percentage of flights arriving within 15 minutes of their scheduled arrivals. The stem-and-leaf plot of the data for one year is below. Picture What would be the class length for creating the frequency histogram?
1.7
In a statistics class, 10 scores were randomly selected with the following results: 74, 73, 77, 77, 71, 68, 65, 77, 67, 66. What is the IQR?
10
The local amusement park was interested in the average wait time at their most popular roller coaster at the peak park time (2 p.m.). They selected 13 patrons and had them get in line between 2 and 3 p.m. Each was given a stopwatch to record the time they spent in line. The times recorded were as follows (in minutes;mean = 114.15): 118, 124, 108, 116, 99, 120, 148, 118, 119, 121, 45, 130, 118. What is the range?
103
The local amusement park was interested in the average wait time at their most popular roller coaster at the peak park time (2 p.m.). They selected 13 patrons and had them get in line between 2 and 3 p.m. Each was given a stopwatch to record the time they spent in line. The times recorded were as follows (in minutes): 118, 124, 108, 116, 99, 120, 148, 118, 119, 121, 45, 130, 118. What is the mean?
114.15
The local amusement park was interested in the average wait time at their most popular roller coaster at the peak park time (2 p.m.). They selected 13 patrons and had them get in line between 2 and 3 p.m. Each was given a stopwatch to record the time they spent in line. The times recorded were as follows (in minutes). 118, 124, 108, 116, 99, 120, 148, 118, 119, 121, 45, 130, 118 What is the first quartile?
116
The local amusement park was interested in the average wait time at their most popular roller coaster at the peak park time (2 p.m.). They selected 13 patrons and had them get in line between 2 and 3 p.m. Each was given a stopwatch to record the time they spent in line. The times recorded were as follows (in minutes): 118, 124, 108, 116, 99, 120, 148, 118, 119, 121, 45, 130, 118. What is the median?
118
The local amusement park was interested in the average wait time at their most popular roller coaster at the peak park time (2 p.m.). They selected 13 patrons and had them get in line between 2 and 3 p.m. Each was given a stopwatch to record the time they spent in line. The times recorded were as follows (in minutes): 118, 124, 108, 116, 99, 120, 148, 118, 119, 121, 45, 130, 118. What is the mode?
118
In a statistics class, 10 scores were randomly selected with the following results (mean = 71.5): 74, 73, 77, 77, 71, 68, 65, 77, 67, 66. What is the range?
12
The local amusement park was interested in the average wait time at their most popular roller coaster at the peak park time (2 p.m.). They selected 13 patrons and had them get in line between 2 and 3 p.m. Each was given a stopwatch to record the time they spent in line. The times recorded were as follows (in minutes). 118, 124, 108, 116, 99, 120, 148, 118, 119, 121, 45, 130, 118 What is the third quartile?
121
The following frequency table summarizes the ages of 60 shoppers at the local grocery store. Picture The sample mean for the above frequency table is calculated as 36.25. Calculate the approximate sample standard deviation for this data set.
13.57
The local amusement park was interested in the average wait time at their most popular roller coaster at the peak park time (2 p.m.). They selected 13 patrons and had them get in line between 2 and 3 p.m. Each was given a stopwatch to record the time they spent in line. The times recorded were as follows (in minutes). 118, 124, 108, 116, 99, 120, 148, 118, 119, 121, 45, 130, 118 What is the 90th percentile?
130
The company financial officer was interested in the average cost of PCs that had been purchased in the past six months. She took a random sample of the price of 10 computers, with the following results. $3,250, $1,127, $2,995, $3,250, $3,445, $3,449, $1,482, $6,120, $3,009, $4,000 What is the 10th percentile?
1304.50
The following table shows the Price-to-Earnings ratio for a stereo equipment manufacturing company between 1998 and 2002. Picture Determine the percentage change in the P/E ratios from 1998 to 1999.
17.74
In a hearing test, subjects estimate the loudness (in decibels) of a sound, and the results are (mean = 70): 68, 67, 70, 71, 68, 75, 68, 62, 80, 73, 68. What is the range?
18
A local electronics retailer recently conducted a study on purchasers of large screen televisions. The study recorded the type of television and the credit account balance of the customer at the time of purchase. They obtained the following results. Picture What percentage of purchases were plasma televisions by customers with the smallest credit balances?
19.60
Quality control is an important issue at ACME Company, which manufactures light bulbs. To test the life-hours of their light bulbs, they randomly sampled nine light bulbs and measured how many hours they lasted (mean = 346.6). 378, 361, 350, 375, 200, 391, 375, 368, 321 What is the range?
191
Suppose that a company's annual sales were $1,200,000 in 1999. The annual growth rate of sales from 1999 to 2000 was 16 percent, from 2000 to 2001 it was −5 percent, and from 2001 to 2002 it was 22 percent. The geometric mean growth rate of sales over this three-year period is calculated as 10.37 percent. Use the geometric mean growth rate and determine the forecasted sales for 2004.
1965337
Compute the sample standard deviation of the data set 6,4,2,1,4,1.
2
Find the z-score for an IQ test score of 142 when the mean is 100 and the standard deviation is 15.
2.8
Compute the population variance of these data: 16,18,23,21,17,16,24,23,9,17,11,16,22,10,15,14
20.5
In a hearing test, subjects estimate the loudness (in decibels) of a sound, and the results are (mean = 70): 68, 67, 70, 71, 68, 75, 68, 62, 80, 73, 68. What is the variance?
22.40
In a statistics class, 10 scores were randomly selected with the following results (mean = 71.5): 74, 73, 77, 77, 71, 68, 65, 77, 67, 66. What is the variance?
22.72
The local amusement park was interested in the average wait time at their most popular roller coaster at the peak park time (2 p.m.). They selected 13 patrons and had them get in line between 2 and 3 p.m. Each was given a stopwatch to record the time they spent in line. The times recorded were as follows (in minutes;mean = 114.15): 118, 124, 108, 116, 99, 120, 148, 118, 119, 121, 45, 130, 118. What is the standard deviation?
23.62
which percentile describes the first quartile
25th
The company financial officer was interested in the average cost of PCs that had been purchased in the past six months. She took a random sample of the price of 10 computers, with the following results. $3,250, $1,127, $2,995, $3,250, $3,445, $3,449, $1,482, $6,120, $3,009, $4,000 What is the first quartile?
2995
A normal population has 99.73 percent of the population measurements within __________ standard deviation(s) of the mean.
3
If the median of a data set is 760, the upper quartile is 950, and the lower quartile is 650, what is the interquartile range?
300
According to a survey of the top 10 employers in a major city in the Midwest, a worker spends an average of 413 minutes a day on the job. Suppose the standard deviation is 26.8 minutes and the time spent is approximately a normal distribution. What are the times within which approximately 99.73 percent of all workers will fall?
332.6,493.4
Quality control is an important issue at ACME Company, which manufactures light bulbs. To test the life hours of their light bulbs, they randomly sampled nine light bulbs and measured how many hours they lasted (mean = 346.6). 378, 361, 350, 375, 200, 391, 375, 368, 321 What is the variance?
3424.3
The company financial officer was interested in the average cost of PCs that had been purchased in the past six months. She took a random sample of the price of 10 computers, with the following results. $3,250, $1,127, $2,995, $3,250, $3,445, $3,449, $1,482, $6,120, $3,009, $4,000 What is the third quartile?
3449
Quality control is an important issue at ACME Company, which manufactures light bulbs. To test the life-hours of their light bulbs, they randomly sampled nine light bulbs and measured how many hours they lasted: 378, 361, 350, 375, 200, 391, 375, 368, 321. What is the mean?
346.6
Quality control is an important issue at ACME Company, which manufactures light bulbs. To test the life-hours of their light bulbs, they randomly sampled nine light bulbs and measured how many hours they lasted: 378, 361, 350, 375, 200, 391, 375, 368, 321. What is the median?
368
Quality control is an important issue at ACME Company, which manufactures light bulbs. Totest the life-hours of their light bulbs, they randomly sampled nine light bulbs and measured how many hours they lasted: 378, 361, 350, 375, 200, 391, 375, 368, 321. What is the mode?
375
According to a survey of the top 10 employers in a major city in the Midwest, a worker spends an average of 413 minutes a day on the job. Suppose the standard deviation is 26.8 minutes, and the time spent is approximately a normal distribution. What are the times within which approximately 68.26 percent of all workers will fall?
386.2,439.8
A local airport keeps track of the percentage of flights arriving within 15 minutes of their scheduled arrivals. The stem-and-leaf plot of the data for one year is below. Picture In developing a histogram of these data, how many classes would be used?
4
In a hearing test, subjects estimate the loudness (in decibels) of a sound, and the results are (mean = 70): 68, 67, 70, 71, 68, 75, 68, 62, 80, 73, 68. What is the standard deviation?
4.73
In a statistics class, 10 scores were randomly selected with the following results (mean = 71.5): 74, 73, 77, 77, 71, 68, 65, 77, 67, 66. What is the standard deviation?
4.77
The company financial officer was interested in the average cost of PCs that had been purchased in the past six months. She took a random sample of the price of 10 computers, with the following results. $3,250, $1,127, $2,995, $3,250, $3,445, $3,449, $1,482, $6,120, $3,009, $4,000 What is the IQR?
454
The local amusement park was interested in the average wait time at their most popular roller coaster at the peak park time (2 p.m.). They selected 13 patrons and had them get in line between 2 and 3 p.m. Each was given a stopwatch to record the time they spent in line. The times recorded were as follows (in minutes). 118, 124, 108, 116, 99, 120, 148, 118, 119, 121, 45, 130, 118 What is the IQR?
5
The number of items rejected daily by a manufacturer because of defects for the last 30 days are: 20, 21, 8, 17, 22, 19, 18, 19, 14, 17, 11, 6, 21, 25, 4, 19, 9, 12, 16, 16, 10, 28, 24, 6, 21, 20, 25, 5, 17, 8 How many classes should be used in constructing a histogram?
5
The number of weekly sales calls by a sample of 25 pharmaceutical salespersons is below. 24, 56, 43, 35, 37, 27, 29, 44, 34, 28, 33, 28, 46, 31, 38, 41, 48, 38, 27, 29, 37, 33, 31, 40, 50 How many classes should be used in the construction of a histogram?
5
if there are 30 values in a data set, how many classes should be created for a frequency histogram
5
The company financial officer was interested in the average cost of PCs that had been purchased in the past six months. She took a random sample of the price of 10 computers, with the following results. $3,250, $1,127, $2,995, $3,250, $3,445, $3,449, $1,482, $6,120, $3,009, $4,000 What is the 90th percentile?
5060
Personnel managers usually want to know where a job applicant ranked in his or her graduating class. With a grade point average of 3.83, Michelle Robinson graduated above the 93rd percentile of her graduating class. What is the percentile rank of a student whose GPA was the median GPA.
50th percentile
The local amusement park was interested in the average wait time at their most popular roller coaster at the peak park time (2 p.m.). They selected 13 patrons and had them get in line between 2 and 3 p.m. Each was given a stopwatch to record the time they spent in line. The times recorded were as follows (in minutes;mean = 114.15): 118, 124, 108, 116, 99, 120, 148, 118, 119, 121, 45, 130, 118. What is the variance?
557.97
Quality control is an important issue at ACME Company, which manufactures light bulbs. To test the life-hours of their light bulbs, they randomly sampled nine light bulbs and measured how many hours they lasted (mean = 346.6). 378, 361, 350, 375, 200, 391, 375, 368, 321 What is the standard deviation?
58.5
If there are 62 values in a data set, how many classes should be created for a frequency histogram?
6
according to chebyshev's theorem, at least what proportion of the data with be within μ ± kσ for k = 1.6?
61%
In a statistics class, 10 scores were randomly selected, with the following results: 74, 73, 77, 77, 71, 68, 65, 77, 67, 66. What is the 10th percentile?
65.5
In a statistics class, 10 scores were randomly selected with the following results: 74, 73, 77, 77, 71, 68, 65, 77, 67, 66. What is the first quartile?
67
In a hearing test, subjects estimate the loudness (in decibels) of a sound, and the results are: 68, 67, 70, 71, 68, 75, 68, 62, 80, 73, 68. What is the median?
68
In a hearing test, subjects estimate the loudness (in decibels) of a sound, and the results are: 68, 67, 70, 71, 68, 75, 68, 62, 80, 73, 68. What is the mode?
68
If there are 120 values in a data set, how many classes should be created for a frequency histogram?
7
In a hearing test, subjects estimate the loudness (in decibels) of a sound, and the results are: 68, 67, 70, 71, 68, 75, 68, 62, 80, 73, 68. What is the mean?
70
In a statistics class, the following 10 scores were randomly selected: 74, 73, 77, 77, 71, 68, 65, 77, 67, 66. What is the mean?
71.5
In a statistics class, the following 10 scores were randomly selected: 74, 73, 77, 77, 71, 68, 65, 77, 67, 66. What is the median?
72
According to Chebyshev's Theorem, at least what proportion of the data will be within μ ± kσ for k = 2?
75%
which percentile describes the third quartile
75th
In a statistics class, 10 scores were randomly selected with the following results: 74, 73, 77, 77, 71, 68, 65, 77, 67, 66. What is the third quartile?
77
In a statistics class, 10 scores were randomly selected, with the following results: 74, 73, 77, 77, 71, 68, 65, 77, 67, 66. What is the 90th percentile?
77
In a statistics class, the following 10 scores were randomly selected: 74, 73, 77, 77, 71, 68, 65, 77, 67, 66. What is the mode?
77
if there are 130 values in a data set, how many classes should be created for a frequency histogram?
8
Using Chebyshev's Theorem, approximate the minimum proportion of the data that will be within μ ± kσ for k = 3.2.
90%
The local amusement park was interested in the average wait time at their most popular roller coaster at the peak park time (2 p.m.). They selected 13 patrons and had them get in line between 2 and 3 p.m. Each was given a stopwatch to record the time they spent in line. The times recorded were as follows (in minutes). 118, 124, 108, 116, 99, 120, 148, 118, 119, 121, 45, 130, 118 What is the 10th percentile?
99
In a Pareto chart, the bar for the "Other" category should be placed to the far left of the chart.
False
a flaw possessed by a population or sample unit is ___
a defect
Which of the following is a type of question used in survey research?
all of the options are correct free response rating dichotomous
a measurement located outside the upper limits of a box and whiskers display is
an outlier
Which of the following graphs is qualitative data?
bar chart
the general term for graphical display of categorical data made up of vertical or horizontal bars is called an___
bar chart
A _____ displays the frequency of each group with qualitative data and a ____ displays the frequency of each group with quantitative data
bar chart, histogram
____ and ___ are used to describe qualitative (categorical) data
bar charts, pie charts
Transactional data are now used by businesses as part of
big data
examining all population measurements is called a
census
A quantity that measures the variation of a population or a sample relative to its mean is called the ____________.
coefficient of variation
The ______________ is a quantity that measures the variation of a population or sample relative to its mean.
coefficient of variation
Which of the following is a measure of the strength of the linear relationship between x and y that is dependent on the units in which x and y are measured.
covariance
if we collect data on the number of wins each team in the NFL had during the 2011-12 season we have ___ data
cross-sectional
___ can be used to study the relationship between two variables
cross-tabulation tables
row or column percentages can be found in
cross-tabulation tables
_________ uses traditional or newer graphics to present visual summaries of business information.
descriptive analytics
____ refers to describing the important aspects of a set of measurements
descriptive statistics
A Yes or No question is _____________.
dichotomous
a data set provides information about some group of individual
elements
When the data being studied are gathered from a published source, this is referred to as an
existing data source
Which of the following is not a supervised learning technique in predictive analytics?
factor analysis
A frequency table includes row and column percentages.
false
A statistical model is a set of assumptions based solely on the sample data that have been selected.
false
An example of a quantitative variable is the manufacturer of a car.
false
Business analytics uses methods that are not part of traditional statistics to look at big data.
false
Daily temperature in a local community collected over a 30-day time period is an example of cross-sectional data.
false
Data summarized in a frequency distribution or histogram form are often called weighted data.
false
If there are seven classes in a frequency distribution, then the fourth class will always contain the median.
false
If we examine some of the population measurements, we are conducting a census of the population.
false
In a data set of information on college business students, an example of an element is their cumulative GPA.
false
It is appropriate to use the Empirical Rule to describe a population that is extremely skewed.
false
Judgment sampling is an example of convenience sampling.
false
Prescriptive analytics involve methods used to find anomalies, patterns, and associations in data sets with the purpose of predicting future outcomes.
false
Range is a better measure of variation than standard deviation.
false
Selecting many different samples and running many different tests can eventually produce a result that makes a desired conclusion be true.
false
The ending value of an initial investment can be calculated using weighted means.
false
The mean is one component of the five-number summary.
false
The median is the measure of central tendency that divides a population or sample into four equal parts.
false
The population mean is the point estimate of the sample mean.
false
The population variance is the average of the squared deviations of the individual population measurements from the population mean.
false
The pth percentile is a value such that (100−p) percent of the measurements fall at or below the value.
false
The range of the measurement is the largest measurement plus the smallest measurement.
false
The science of describing the important aspects of a set of measures is called statistical inference.
false
The target population is the result of sampling from the original population that is of interest to the researcher.
false
Time series data are data collected at the same time period.
false
When data are qualitative, the bars should never be separated by gaps.
false
When establishing the classes for a frequency table, it is generally agreed that the more classes you use the better your frequency table will be.
false
When we wish to summarize the proportion (or fraction) of items in a class, we use the frequency distribution for each class.
false
Z-score is often used as a measure of risk.
false
a low response rate has no effect on the validity of a survey's findings
false
a scatter plot can be used to identify outliers
false
errors of non-observation occur when data values are recorded incorrectly
false
in an experimental study, the aim is to manipulate or set the value of the response variable
false
in order to select a stratified random sample, we divide the population into overlapping groups of similar elements
false
the term big data was derived from the use of survey data
false
when the data are qualitative, the bars should never be separated by gaps
false
a population that consists of all the customers who will use the drive-thru of the local fast food restaurant is called a
finite population
A ____ is list of all the units in a population
frame
the number of measurements failing within a class interval is called the ___
frequency
The constant return used to forecast future wealth based on actual time periods and their returns is the ____________
geometric mean
a graphical portrayal of quantitative data set that divides the data into classes and gives the frequency of each class is a
histogram
all of the following are used to describe qualitative data except the
histogram
which one of the following graphical tools is used with quantitative data?
histogram
As the coefficient of variation _______________, risk ______________.
increases, increases
Statistical ____________ refers to using a sample of measurements and making generalizations about the important aspects of a population.
inference
a ratio variable has the following characteristic
inherently defined zero value
College entrance exam scores, such as SAT scores, are an example of an ____ variable
interval
Temperature (in degrees Fahrenheit) is an example of a ___ variable
interval
the two types of quantitative variables are
interval and ratio
The process of assigning a value of a variable to each element in a data set is called ___________.
measurement
Which of the following is influenced the least by the occurrence of extreme values in a sample?
median
another name for the 50th percentile is the
median
Which of the following is a quantitative variable?
mileage of a car
The measurement in a sample or a population that occurs most frequently is the ___________.
mode
a ____ variable is a qualitative variable such that there is no meaning ordering or ranking of the categories
nominative
__________ is a necessary component of a runs plot.
observation over time
Measurements from a population are called
observations
An identification of police offers by rank would represent a ___ level of measurements
ordinal
a _____ can be used to differentiate the "vital few" causes of quality problems from the "trivial many" causes of quality problems
pareto chart
all of the following are used to describe quantitative data except the
pie chart
data that are collected by an individual through personally planned experimentation or observation are
primary data
____ sampling is where we know the chance that each element will be included in the sample, which allows us to make statistical inferences about the sample population
probability
one method of determining whether a sample being studied can be used to make statistical inferences about the population is to
produce a runs plot
a __ variable can have values that indicate into which of several categories of a population it belongs
qualitative
A _____ variable can have values that are numbers on the real number line
quantitative
The change in the daily price of a stock is what type of variable?
quantitative
All of the following are measures of central tendency except the ____________.
range
As a measure of variation, the sample ___________ is easy to understand and compute. It is based on the two extreme values and is therefore a highly unstable measure.
range
The number of miles a truck is driven before it is overhauled is an example of a ___ variable
ratio
The weight of a chemical compound used in an experiment that is obtained using a well adjusted scale represents a ___ level of measurement
ratio
the percentage of measurements in a class is caled the ___ of that class
relative frequency
A ___ is a subset of the units in a population
sample
The point estimate of the _______________ is the positive square root of the sample variance.
sample standard deviation
Methods for obtaining a sample are called
sampling designs
_____________ is the difference between a numerical description of the population and the corresponding descriptor of the sample.
sampling error
a plot of the values of two variables is a ___ plot
scatter
a ____ shows the relationship between two variables
scatter plot
Data collected for a particular study are referred to as a data ____________.
set
If the mean is greater than the median, then the distribution is ___________.
skewed right
if the mean is greater than the median, then the distribution is
skewed right
a histogram that tails out toward smaller values is
skewed to the left
A relative frequency curve having a long tail to the right is said to be ___
skewed to the right
a histogram that tails out toward larger values in ___
skewed to the right
The number of weekly sales calls by a sample of 25 pharmaceutical salespersons is below. 24, 56, 43, 35, 37, 27, 29, 44, 34, 28, 33, 28, 46, 31, 38, 41, 48, 38, 27, 29, 37, 33, 31, 40, 50 What is the shape of the distribution of the data?
skewed with tail to the right
in the least squares line ___ is defined as rise/run`
slope
a ____ is a set of assumptions about how sample data are selected and about the population from which the sample data are selected
statistical model
non-overlapping groups in random sampling of a population are called
strata
An example of manipulating a graphical display to distort reality is ___
stretching the axes
If we collect data on the number of wins the dallas cowboys earned each of the pas 10 years we have ___ data
time series
an interval that contains a specified percentage of the individual measurements is called a ___ interval
tolerance
___ consists of a set of concepts and techniques that are used to describe population and samples
traditional statistics
A bar chart is a graphic that can be used to depict qualitative data.
true
A correlation coefficient close to −1 says x and y are highly related.
true
A runs plot is a form of scatter plot.
true
Beginning the vertical scale of a graph at a value different from zero can cause increases to look more dramatic.
true
By taking a systematic sample in which we select every 100th shopper arriving at a specific store, we are approximating a random sample of shoppers.
true
Chebyshev's Theorem is only of practical use when analyzing a non-mound-shaped population that is not very skewed.
true
Cross-sectional data are data collected at the same point in time.
true
Data warehousing is defined as a process of centralized data management and retrieval.
true
If we sample without replacement, we do not place the unit chosen on a particular selection back into the population.
true
In a symmetric population, the median equals the mode.
true
In systematic sampling, the first element is randomly selected from the first (N/n) elements.
true
In the calculation of a mean for grouped data, we assume that the average of the measurements in each class equals the class midpoint.
true
In the first step of setting up a Pareto chart, a frequency table should be constructed of the defects (or categories) in decreasing order of frequency.
true
It is possible to create different interpretations of the same graphical display by simply using different captions.
true
Judgment sampling occurs when a person who is extremely knowledgeable about the population under consideration selects the population element(s) that they feel is(are) most representative of the population.
true
Primary data are data collected by an individual.
true
Sampling error can occur because of incomplete information.
true
Secondary data are data taken from an existing source.
true
Statistical inference is the science of using a sample of measurements to make generalizations about the important aspects of a population of measurements.
true
The median is said to be resistant to extreme values.
true
The median is the value below which and above which approximately 50 percent of the measurements lie.
true
The mode is the measurement in a sample or population that occurs most frequently.
true
The number of sick days per month taken by employees for the last 10 years at Apex Co. is an example of time series data.
true
The population mean is the average of the population measurements.
true
The weights that are used in calculating a weighted mean will vary depending on the situation.
true
When constructing any graphical display that utilizes categorical data, classes that have frequencies of 5 percent or less are usually combined together into a single category.
true
a common practice in selecting a sample from a large geographic area is multistage cluster sampling
true
a population is a set of existing units
true
a recording error is an error of observation
true
cross-sectional data are data collected at the same point in time
true
processes produce outputs over time
true
sampling error occurs because a mean of a random sample can not exactly equal the population mean that we are attempting to estimate
true
the relative frequency is the frequency of a class divided by the total number of measurements
true
using a nonrandom sample procedure in order to support a desired conclusion is an example of an unethical statistical procedure
true
____ occurs when some population elements are excluded from the process of selecting the sample
undercoverage
Which of the following is not an example of unethical statistical practices?
using graphs to make statistical inferences
Any characteristic of a population unit is a(n)
variable
any characteristic of an element is called a
variable
The average of the squared deviations of the individual population measurement from the population mean is the ___________.
variance
which of the following is a categorical variable
whether a person has a traffic violation