homework
If there are 130 values in a data set, how many classes should be created for a frequency histogram?
8
T or F? In an experimental study, the aim is to manipulate or set the value of the response variable.
F
T or F? The number of sick days taken by employees in 2008 for the top 10 technology companies is an example of time series data.
F
T or F? The term big data refers to the use of survey data by big business.
F
T or F? Time series data are data collected at the same time period.
F
The geometric mean is the rate of change that yields better wealth at the end of a set of time periods than the actual returns.
F
The median is the measure of central tendency that divides a population or sample into four equal parts.
F
The population mean is the point estimate of the sample mean.
F
The range of the measurement is the largest measurement plus the smallest measurement.
F
When data are qualitative, the bars should never be separated by gaps.
F
When we wish to summarize the proportion (or fraction) of items in a class, we use the frequency distribution for each class.
F
A bar chart is a graphic that can be used to depict qualitative data.
T
A runs plot is a form of scatter plot.
T
A stem-and-leaf display is a graphical portrayal of a data set that shows the data set's overall pattern of variation.
T
In a symmetric population, the median equals the mode.
T
T or F? A population is a set that includes all elements about which we wish to draw a conclusion.
T
T or F? A random sample is selected so that every element in the population has the same chance of being included in the sample.
T
T or F? Cross-sectional data are data collected at the same or approximately the same point in time.
T
T or F? Data warehousing is defined as a process of centralized data management and retrieval.
T
T or F? In an observational study, the variable of interest is called a response variable.
T
T or F? In systematic sampling, the first element is randomly selected from the first (N/n) elements.
T
The stem-and-leaf display is advantageous because it allows us to actually see the measurements in the data set.
T
When looking at the shape of the distribution using a histogram, a distribution is skewed to the right when the left tail is shorter than the right tail.
T
A ________ displays the frequency of each class with qualitative data and a ________ displays the frequency of each class with quantitative data.
bar chart, histogram
The number of miles a truck is driven before it is overhauled is an example of a(n) ________ variable.
ratio
Which of the following is not a graphical tool for descriptive analytics (dashboards)?
raw data
________ is the difference between a numerical descriptor of the population and the corresponding descriptor of the sample.
sampling error
A plot that allows us to visualize the relationship between two variables is a(n) ________ plot.
scatter
A histogram that has a longer tail extending toward smaller values is ________.
skewed to the left
A histogram that has a longer tail extending toward larger values is ________.
skewed to the right
define sample
subset of the units in a population.
If the mean, median, and mode for a given population are all equal and the relative frequency curve has matching tails to the right and left, then we would describe the shape of the distribution of the population as ________.
symmetrical
Pareto charts are frequently used to identify ________.
the most common types of defects
If we collect data on the number of wins the Dallas Cowboys earned each of the past 10 years, we have ________ data.
time series
________ occurs when some population elements are excluded from the process of selecting the sample.
undercoverage
Any characteristic of an element is called a ________.
variable
T or F? An example of a quantitative variable is the manufacturer of a car.
F
According to Chebyshev's theorem, a range of how many standard deviations would include at least 80 percent of the values?
2.2
A scatter plot can be used to identify outliers.
F
It is appropriate to use the Empirical Rule to describe a population that is extremely skewed.
F
T or F? A quantitative variable can also be referred to as a categorical variable.
F
T or F? An example of a qualitative variable is the mileage of a car.
F
As a business owner, I have requested my staff to develop a set of dashboards that can be used by the public to show wait time at each of my four local coffee shops at peak times during the day and whether the time is short, medium, or long. Which of the following graphical displays would be the best choice?
bullet graph
A stem-and-leaf display is best used to ________.
display the shape of the distribution
define census
examine all of the population units.
If a data set consists of 1,000 measurements, would you summarize the data set using a histogram or a dot plot?
histogram
Which of the following divides quantitative measurements into classes and graphs the frequency, relative frequency, or percentage frequency for each class?
histogram
As the coefficient of variation ________, risk ________.
increases, increases
The two types of quantitative variables are
interval and ratio
A person's telephone area code is an example of a(n) ________ variable.
nominative
Jersey numbers of soccer players is an example of a(n) ________ variable.
nominative
When developing a frequency distribution, the class (group) intervals must be ________.
nonoverlapping
Measurements from a population are called
observations
Quantitative or qualitative? The advertising medium (radio, television, or print) used to promote a product.
qual
Quantitative or qualitative? The stock exchange on which a company's stock is traded.
qual
Quantitative or qualitative? The dollar amount on an accounts receivable invoice.
quan
Quantitative or qualitative? The national debt of the United States in 2017.
quan
Quantitative or qualitative? The net profit for a company in 2017.
quan
The change in the daily price of a stock is what type of variable?
quantitative
