Exam 1: Describing Data With Graphs

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 15 test scores for the history midterm are listed below. Construct and interpret a character 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

Which of the following numbers constitutes the sum of the relative frequencies found in a relative frequency distribution for quantitative data?

A relative frequency distribution is a tabular summary of a data set showing the proportions of all observations which fall into each of several collectively exhaustive and mutually exclusive classes.

A bar chart and a histogram can be used interchangeably.

A pie chart is a portrayal of divisions of some aggregate by a segmented circle in such a way that the sector areas are proportional to the sizes of the divisions in question.

Friendly Encounter The Executive Board of a popular online dating website, called Friendly Encounter, wanted to know how to market the site by targeting the age groups most likely to be interested in its product. To find out, a random sample of 250 users was drawn from its database of participants who had been active during the previous month. The users were then categorized into age groups. The average frequency of access per week was recorded for each age group. The result was organized into the following table of data: -Refer to the Friendly Encounter table. From this sample data, what may the Executive Board deduce about the approximate percentage of its dating site users being 40 years of age and over?

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

Garbage Weight A garbage carrier would like to start charging by the weight of a customer's garbage rather than the number of cans. The weights (in kilograms) of 90 randomly selected cans of garbage are summarized in the chart below. -Refer to the Garbage Weight table. Find the relative frequency of each class.

A distribution is skewed to the left if it contains a few unusually large measurements.

Which of the following should generally NOT be used when constructing a relative frequency histogram?

What are the characteristics of experimental units generally called?

Garbage Weight A garbage carrier would like to start charging by the weight of a customer's garbage rather than the number of cans. The weights (in kilograms) of 90 randomly selected cans of garbage are summarized in the chart below. -Refer to the Garbage Weight table. What percentage of the cans weigh less than 20.9 kilograms?

Which of the following is NOT a goal of descriptive statistics?

Stem-and-leaf plots are often used to analyze qualitative data in most real-life applications.

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

On what does the total area of the bars in a relative frequency histogram depend?

Potato Preferences A study was performed to examine preferences for various types of potatoes: mashed, french fries, hash browns, steak fries, and baked. The following data were recorded regarding the preferences of 150 people: -Refer to the Potato Preferences table. Construct a bar chart to describe the data.

Which of the following terms refers to a graphical presentation of data that is displayed in order of descending magnitude?

For the same data, a relative frequency histogram will look exactly the same as a frequency histogram.

Which of the following choices best describes the methods dealt with by the branch of statistics called descriptive statistics?