ECON10 chapter1
A branch of the statistics discipline that is used to develop and utilize techniques for effectively presenting numerical information is called inferential statistics.
False
A relative frequency histogram can be constructed by letting the horizontal axis or the vertical axis represent the variable of interest.
False
A relative frequency histogram can be constructed for qualitative as well as quantitative data.
False
A stem and leaf plot describes two-digit integers between 30 and 80. For one of the classes displayed, the row appears as 5|234. The numerical values being described are 25, 35, and 45.
False
A tabular summary of categorical data set showing the number of observations that fall into each of several collectively exhaustive and mutually exclusive classes is called a bar chart.
False
Individual observations within each class may be found in a frequency distribution.
False
Persons or objects that have characteristics of interest to statisticians are called variables.
False
Relative frequency distributions are specifically constructed for analyzing discrete data.
False
Stem and leaf plots are often used to analyze qualitative data in most real life applications.
False
The class interval in a frequency distribution is the number of data values falling within each class.
False
The four classes: less than 5, 5 to < 10, 10 to < 20, greater than 20, would be acceptable for developing a frequency distribution.
False
When a distribution has a greater proportion of the measurements to the left of the peak value, we say that it is skewed to the right.
False
When a distribution has a greater proportion of the measurements to the right of the peak value, we say that it is skewed to the left.
False
When constructing a relative frequency distribution, if the data are discrete, it will always be necessary to develop class boundaries.
False
A listing of data in order of ascending or descending magnitude is called: a frequency distribution a relative frequency distribution a relative frequency histogram none of these all of these
none of these
Which of the following is not recommended when constructing a relative frequency histogram?
open-ended classes
The common graphical presentation of qualitative data is the:
pie chart
A histogram is a graphical device that is commonly used to analyze:
quantitative data
The stem and leaf plot is used to display the distribution of:
quantitative data
The sum of the frequencies for all classes will always equal:
the total number of observations in the data set
A variable that is normally described in words rather than numerically is a qualitative variable.
true
Characteristics possessed by experimental units are called:
variables
Statistical inference is the process of making an estimate, prediction, or decision about a population based on sample data.
True
The difference between a histogram and a bar chart is that the histogram represents quantitative data while the bar chart represents qualitative data.
True
The largest value in a set of data is 100, and the lowest value is 20. If the resulting frequency distribution is to have five classes of equal width, the class width will be 16.
True
The total area of the six bars in a relative frequency histogram for which the width of each bar is five units is 5.
True
Time series data are often graphically depicted on a line chart, which is a plot of the variable of interest over time.
True
Twenty-five percent of a sample of 200 professional tennis players indicated that their parents did not play tennis. This is an example of descriptive statistics as opposed to inferential statistics.
True
The total area of the bars in a relative frequency histogram: depends on the sample size depends on the number of bars depends on the width of each bar depends on the population size depends on the frequency
depends on the width of each bar
Which of the following is not the goal of descriptive statistics?
estimating characteristics of the population based on a sample
The total area of the six bars in a relative frequency histogram for which the width of each bar is ten units is:
10
Given 180 observations, a data class with an absolute class frequency of 36 must have a relative class frequency of:
36*180=0.2
The sum of relative frequencies found in a relative frequency distribution for quantitative data necessarily equals:
1
Which of the following statements is false?
A bar chart and histogram can be used interchangeably.
Which of the following statements is true?
All of these.
Which of the following statements is true?
Both univariate data result when a single variable is measured on a single experimental unit and multivariate data result when more than two variables are measured are true.
The set of all possible observations about a specified characteristic of interest is:
Population
A branch of the statistics discipline that is used to develop and utilize techniques for properly making inferences about population characteristics from information contained in a sample drawn from this population is called inferential statistics.
True
A discrete quantitative variable is one that can assume values only at specific points on an interval of values, with inevitable gaps between them.
True
A histogram is said to be symmetric if, when we draw a vertical line down the center of the histogram, the two sides are identical in shape and size.
True
A local cable system using a sample of 1000 subscribers estimates that fifty percent of its subscribers watch premium channel at least five times per week. This is an example of inferential statistics as opposed to descriptive statistics.
True
A relative frequency distribution describes the proportion of data values that fall within each class, and may be presented in a histogram form.
True
A relative frequency distribution describes the proportion of data values that fall within each class.
True
A relative frequency distribution is a tabular summary of a data set showing the proportions of all observations that fall into each of several collectively exhaustive and mutually exclusive classes.
True
A skewed histogram is one with a long tail extending either to the right or to the left.
True
A variable is a characteristic that changes or varies over time, and/or for different individuals or objects under consideration. An experimental unit is the individual or object on which a variable is measured.
True
Bar and pie charts are graphical techniques for qualitative data. The former focus the attention on the frequency of the occurrences of the categories, and the later emphasize the percentage of occurrences of each category.
True
Bar charts can typically be formed with the bars vertical or horizontal without affecting the interpretation.
True
Compared to the relative frequency histogram, the stem and leaf plot provides more details, since it can describe the individual data values as well as show how many are in each group, or stem.
True
For the same data, a relative frequency histogram will have the same overall shape as a frequency histogram.
True
Persons or objects on which an experiment is performed are called experimental units.
True
Which of the following statements is false?
When constructing a frequency distribution for categorical data, it will always be necessary to develop class boundaries.
The best type of chart for comparing two sets of qualitative data is:
a bar chart
A histogram is usually used to display which of the following characteristics for a quantitative variable? the shape of the distribution the spread or variability in the data the approximate center of the data the spread or variability in the data and the approximate center of the data all of these
all of these
A common rule of thumb in constructing a relative frequency histogram is to use:
between 5 and 12 classes
You asked ten of your classmates about their weight. Based on this information, you stated that the average weight of all students in your university or college is 158 pounds. This is an example of:
statistical inference