Exam 1: Describing Data With Graphs

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.

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.

A relative frequency distribution describes the proportion of data values that fall within each class, and may be presented in a histogram form.

A listing of data in order of ascending or descending magnitude is called:

Time series data are often graphically depicted on a line chart, which is a plot of the variable of interest over time.

A histogram is a graphical device that is commonly used to analyze:

One of the differences between a bar chart and a histogram is that a histogram typically displays data in a percentage form.

A single observation about s specified characteristic of interest is:

Given 180 observations, a data class with an absolute class frequency of 36 must have a relative class frequency of:

The total area of the six bars in a relative frequency histogram for which the width of each bar is ten units is:

In a sample of 1000 students in a university, 125 of them or 12.5% are biology majors. The 12.5% is an example of statistical inference.

Characteristics possessed by experimental units are called:

A math teacher would like to present the midterm results to her class in a way that shows the overall spread of the data. The 25 test scores for the midterm are listed below. a. Construct a dotplot. 45 78 62 98 50 61 91 89 57 64 77 69 82 73 70 73 79 80 68 72 62 65 78 50 95 b. Explain what the plot tells us. ________________________________________________________

The librarian of a small community library has compiled the number of people who visited the library and the respective number of checked-out books, and created the line chart shown below: Interpret the chart, where the solid line is the number of visitors and the dashed line is the number of books checked-out. ________________________________________________________

A bar chart is used to display a:

A qualitative variable about which observations can be made in only two categories is a bivariate data set.

Persons or objects that have characteristics of interest to statisticians are called variables.

The freshness and overall quality of milk depend upon the type of packaging used. The manager of a dairy company is considering changing the packaging from cartons to plastic. The quality control team of this dairy company packaged milk in 100 containers of each type of material. After a specific amount of time, the team tested the milk for freshness and overall quality. Identify the population and sample in this problem. Population: ________________________________________________________ Sample: ________________________________________________________

The set of all possible observations about a specified characteristic of interest is:

The data values plotted on a line graph are connected with a straight line between each pair of successive points.