Question 1

A skewed histogram is one with a long tail extending either to the right or left.

Accepted Answer

A skewed histogram is one where the distribution is not symmetrical, and there is a long tail on either side of the central peak. If the tail extends to the right, it is considered a right-skewed histogram, and if it extends to the left, it is considered a left-skewed histogram.

Question 2

A histogram is said to be symmetric if, when we draw a vertical line down the centre of the histogram, the two sides are identical in shape and size.

Accepted Answer

A symmetric histogram has a balanced distribution with equal frequencies on both sides of the centre line.

Question 3

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

Accepted Answer

Stem and leaf plots are used to analyze quantitative data, as they display numerical information.

Question 4

If you wish to compare two data sets of different sizes, it is usually a good idea to convert frequency distributions to relative frequency distributions.

Accepted Answer

Converting frequency distributions to relative frequency distributions allows for a more meaningful comparison of the two data sets, as the relative frequencies represent the proportion of each category in relation to the total number of observations in the dataset. This standardizes the data and makes it easier to compare datasets of different sizes.

Question 5

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.

Accepted Answer

This accurately describes the definition of a pie chart.

Question 6

When a distribution has more values to the right and tails to the left, then it is considered to be skewed to the right.

Accepted Answer

A distribution with more values to the right and tails to the left is considered to be skewed to the left, not the right.

Question 7

Bar charts can typically be formed with the bars vertical or horizontal without affecting the interpretation.

Accepted Answer

This is true. The choice of having vertical or horizontal bars in a bar chart is a matter of personal preference or convention, but it does not affect the interpretation of the data.

Question 8

The four classes: 0 to < 5, 5 to < 10, 10 to < 20, over 20, would be acceptable for developing a frequency distribution.

Accepted Answer

The answer of The four classes: 0 to < 5,...

Question 9

If the six bars of a relative frequency histogram each have a width of five units, then the total area is 5.

Accepted Answer

The total area of a relative frequency histogram is always 1, regardless of the number of bars or the width of each bar.

Question 10

The class interval in a frequency distribution is the number of data values falling within each class.

Accepted Answer

The class interval in a frequency distribution is the range of values included in each class, not the number of data values that fall within each class.

Question 11

A relative frequency histogram can be constructed by letting either the horizontal axis or the vertical axis represent the variable of interest.

Accepted Answer

In a relative frequency histogram, the horizontal axis represents the variable of interest, while the vertical axis represents the relative frequency of the data.

Question 12

When a distribution has more values to the left and tails to the right, then it is considered to be skewed to the left.

Accepted Answer

A distribution with more values to the left and a tail to the right is considered to be skewed to the right.

Question 13

When constructing a relative frequency distribution, if the data are discrete, it will always be necessary to develop class boundaries.

Accepted Answer

Class boundaries are only necessary for continuous data, not discrete data. Discrete data can be easily grouped into categories without the need for boundaries.

Question 14

A relative frequency histogram can be constructed for qualitative as well as quantitative data.

Accepted Answer

A relative frequency histogram is constructed specifically for quantitative data to show the relative frequencies of measurements in different intervals; it is not suitable for qualitative data, which are better represented by bar charts or pie charts.

Question 15

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

Accepted Answer

A histogram displays data in a frequency distribution, not in a percentage form.

Question 16

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

Accepted Answer

The answer of For the same data, a relative frequency...

Question 17

Suppose you are given a stem-and-leaf plot that describes two-digit integers between 30 and 80. For one of the classes displayed, the row appears as 5|234. In this case, the numerical values being described are 25, 35, and 45.

Accepted Answer

The stem is 5 and the leaf values are 2, 3, and 4. Therefore, the numerical values being described are 52, 53, and 54, which are three-digit integers, not two-digit integers between 30 and 80.

Question 18

A dotplot is a graphical portrayal of an absolute or relative frequency distribution of continuous quantitative data having the following characteristics:
a. the lower and upper limits of the data classes are identified by tick marks on a horizontal axis, and
b. the corresponding absolute or relative class frequencies are represented by the areas of contiguous rectangles that stand on top of each of these class intervals.

Accepted Answer

The description provided in the statement is actually referring to a histogram, not a dotplot. In a dotplot, each data point is represented by a dot on a horizontal axis, with multiple dots stacked vertically if there are multiple data points with the same value.

Question 19

Relative frequency distributions are specifically constructed for analyzing discrete data.

Accepted Answer

Relative frequency distributions can be used for both discrete and continuous data to show the proportion of observations within each category or interval.

Question 20

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

Accepted Answer

This statement is true. Line charts are commonly used to display time series data, with time displayed on the horizontal axis and the variable of interest on the vertical axis.

Quiz 1: Describing Data With Graphs