Question 1

The shape of the data set summarized in the stem-and-leaf diagram is best described as:

Accepted Answer

The stem-and-leaf diagram shows that the data is clustered towards the lower end of the distribution with a long tail towards the higher values. This indicates a positive skewness in the data, and thus, choice D is the best option.

Question 2

The sum of all the relative frequencies of classes up to and including a particular class is defined as the:

Accepted Answer

The sum of all the relative frequencies of classes up to and including a particular class is known as the cumulative relative frequency. It provides a running total of the frequencies and is useful in determining the percentage or proportion of data points below a certain value. A, B, and D are not correct because they do not describe this specific concept.

Question 3

This histogram shows the age at which 548 patients were first diagnosed with diabetes.The shape of this histogram is best described as:

Accepted Answer

B

Question 4

A distribution with only one peak is called:

Accepted Answer

A distribution with only one peak is called unimodal.

Question 5

To assure prompt service, the city metro routinely records wait times at its various bus stops.The length of time a customer must wait for a bus is recorded to the nearest second.What type of data are these?

Accepted Answer

The wait times are recorded to the nearest second, which means they are countable and distinct values, making them discrete data.

Question 6

If there are more than two observations on the same person, the data set is:

Accepted Answer

Since there are multiple observations on the same person, the data set is multivariate. Bivariate data sets only have two variables being measured. Random and univariate are not relevant to this situation.

Question 7

A student counted the number of candies of each color in a bag of 57 Reese's Pieces.The results are shown in the bar graph.  How many of the candies were colored orange?

Accepted Answer

The answer of A student counted the number of candies...

Question 8

Judging from this stem-and-leaf display, the data set appears to be:

Accepted Answer

The answer of  Judging from this stem-and-leaf display, the...

Question 9

A student wants to use a curve to represent the number of students in each class over the school day.The student's friend says a bar chart should be used.Who is correct, and why?

Accepted Answer

Since the data on class sizes are discrete, a bar chart should be used instead of a curve which implies continuous data. A bar chart would show the exact number of students in each class, providing a more accurate representation of the data.

Question 10

Concerning qualitative data, the ______________ of a particular class is the frequency of the class divided by the total number of observations.

Accepted Answer

The definition given in the question matches with the concept of relative frequency, which is calculated by dividing the frequency of a class by the total number of observations. Therefore, option A is the correct answer. Option B (numeric center) is not relevant to qualitative data, and option C (frequency) only gives the number of times a certain value appears in the data.

Question 11

Concerning univariate data, a _____________ or ______________ data set consists of non-numerical observations that may be placed in categories.

Accepted Answer

A categorical or qualitative data set consists of non-numerical observations that may be placed in categories. On the other hand, a numerical or quantitative data set consists of numerical observations that represent measurable quantities.

Question 12

A survey records the number of U.S.states each person has visited.This is an example of what type of data?

Accepted Answer

The number of U.S. states each person has visited is a count of distinct items, making it discrete data. Discrete data can only take on certain values (e.g., whole numbers).

Question 13

Concerning qualitative data, the _____________ of a particular class is the count for that class.

Accepted Answer

Frequency refers to the count or number of times a particular class or category appears in the data set. This is important when analyzing qualitative data as it provides insights into which categories are most commonly occurring. Relative frequency is the proportion of each class relative to the total number of observations, while distribution refers to the pattern of how the classes are spread out throughout the dataset. Probability is a measure of the likelihood of an event occurring in a random experiment, and is more commonly associated with quantitative data.

Question 14

What data value is represented by the bold and underlined "1" in the stem-and-leaf diagram? (Note: It is bold and underlined for emphasis only.)

Accepted Answer

The answer of  What data value is represented by...

Question 15

What data value is represented by the bold and underlined "0" in the stem-and-leaf diagram? (Note: It is bold and underlined for emphasis only.)

Accepted Answer

In the stem-and-leaf diagram, the stem is "40" and the leaf unit is "0.1". Therefore, the bold and underlined "0" represents a data value of 400.

Question 16

A survey records a person's smoking status as either "yes" or "no." This survey is recording what kind of data?

Accepted Answer

The data is categorical (divided into categories), and qualitative (describing a quality or characteristic rather than a quantity or numerical value).

Question 17

Two statistics students are arguing over which type of bar graph to use.One insists that a bar graph that displays the relative frequency will be better for displaying the overall shape of the data.The other holds that only a frequency bar graph will suffice.You happen along and hear their conversation.What advice do you give them?

Accepted Answer

Both relative frequency and frequency bar graphs display the same overall shape of the data; they only differ in the scale used on the y-axis.

Question 18

What is the value of the data point represented by the bold and underlined "0" in the stem-and-leaf diagram? (Note: It is bold and underlined for emphasis only.)

Accepted Answer

The answer of  What is the value of the...

Question 19

This stem-and-leaf plot shows the lengths of reigns (in years) of the British monarchs.According to the plot, how many British rulers had reigns that lasted less than a full year?

Accepted Answer

The stem-and-leaf plot shows three rulers with a leaf of 0.1, indicating a reign of less than a year (0.6, 0.9, and 0.8).

Question 20

Relative frequency is best suited to describing __________________ data.

Accepted Answer

Relative frequency is a method of describing the proportion of different categories in a dataset, which is best suited to qualitative data. Continuous and quantitative data require more specific statistical techniques, while multivariate data involves analyzing the relationships between multiple variables.

Quiz 3: Tables and Graphs for Summarizing Data