Q: What is the formula for calculating the class midpoint in a frequency distribution?

$$\frac{\text{Lower class limit} + \text{Next consecutive lower class limit}}{2}$$

Question 1

Which of the following best describes a Pareto chart, as shown in the images above?

Accepted Answer

A bar chart where the bars are arranged in decreasing order of frequency or relative frequency.

Question 2

Given the frequency table for eye color, what is the relative frequency of green eyes if there are 33 observations in total?

Accepted Answer

$$\frac{6}{33} \approx 0.1818$$

Question 3

Which type of graph is most appropriate for displaying the cumulative frequency of a quantitative variable?

Accepted Answer

Ogive

Question 4

A histogram is different from a bar graph in that:

Accepted Answer

The bars in a histogram must touch each other, representing continuous data.

Question 5

If the minimum salary in a data set is $$70,000 and the maximum is 190$$,823, what is the range?

Accepted Answer

$$120,823$$

Question 6

Which of the following is NOT a common way to misrepresent data in a graph?

Accepted Answer

Using an even scale on the axes.

Question 7

What is the formula for calculating the class midpoint in a frequency distribution?

Accepted Answer

$$\frac{	ext{Lower class limit} + 	ext{Next consecutive lower class limit}}{2}$$

Question 8

A pie chart is most appropriate for which type of data?

Accepted Answer

Qualitative data

Question 9

Which of the following best describes a cumulative relative frequency distribution?

Accepted Answer

It displays the proportion of observations less than or equal to the upper class limit for each class.

Question 10

If a class in a frequency table has a lower class limit of 110,000 and the next consecutive lower class limit is 130,000, what is the class width?

Accepted Answer

$$130,000 - 110,000 = 20,000$$

Question 11

Which graph would be most appropriate to show the change in the cost of an item over several years?

Accepted Answer

Time series plot

Question 12

A dot plot is especially useful for which type of data?

Accepted Answer

Data sets with many repeated values

Question 13

Which of the following statements about frequency polygons is correct?

Accepted Answer

They use points connected by line segments to represent frequencies for the classes.

Question 14

If a class in a cumulative frequency table has a cumulative frequency of 34 and the next class has a cumulative frequency of 39, how many observations are in the next class?

Accepted Answer

$$39 - 34 = 5$$

Question 15

Which of the following is a key difference between a bar graph and a histogram?

Accepted Answer

A bar graph is used for qualitative data, while a histogram is used for quantitative data.

Question 16

In a frequency distribution, what is the sum of all relative frequencies?

Accepted Answer

$$1$$

Question 17

Which of the following is true about open-ended classes in a frequency table?

Accepted Answer

They occur when the first or last class has no limit.

Question 18

If a data set has a lot of repeated values within a small range, which graphical method is most appropriate?

Accepted Answer

Stem-and-leaf plot

Question 19

Which of the following best describes the purpose of a cumulative frequency distribution?

Accepted Answer

To display the total number of observations less than or equal to each class limit.

Question 20

If the frequency of a class is 9 and the sample size is 50, what is the relative frequency?

Accepted Answer

$$\frac{9}{50} = 0.18$$

Describing Data with Tables and Graphs: Frequency Distributions and Graphical Representations

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