Q: A survey of 1,145 people asked them to rate the quality of care in an emergency room as Very Good (527), Good (492), Poor (80), or Very Poor (46). What percentage rated the care as Good? Use the formula: $$\text{Percentage} = \frac{\text{Frequency}}{\text{Total}} \times 100$$

$$\frac{492}{1145} \times 100 \approx 43\%$$

Question 1

Which of the following best describes the type of data that a histogram is used to display?

Accepted Answer

Quantitative data

Question 2

A company wants to compare the market share of five smartphone brands. Which graphical tool is most appropriate for this purpose?

Accepted Answer

Pie chart

Question 3

Given the following frequency distribution for the number of iPads sold per day, what is the relative frequency for selling 3 iPads?

0: 5
1: 8
2: 14
3: 13
4: 6
5: 4
Total: 50

Accepted Answer

$$\frac{13}{50} = 0.26$$

Question 4

A cumulative relative frequency distribution is most useful for answering which of the following questions?

Accepted Answer

What proportion of observations fall below a certain value?

Question 5

A histogram is constructed for the wait times (in minutes) of 50 customers, grouped into 6 classes. If the minimum wait time is 0.6 and the maximum is 17.4, what is the estimated class width?

Use the formula: $$	ext{Class Width} = \frac{	ext{Max} - 	ext{Min}}{k}$$

Accepted Answer

$$\frac{17.4 - 0.6}{6} = 2.8$$

Question 6

Which of the following is NOT a rule for constructing classes for grouped data in a frequency distribution?

Accepted Answer

Open-ended classes are preferred

Question 7

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

Accepted Answer

Categorical (qualitative) data

Question 8

A contingency table is used to:

Accepted Answer

Display the frequencies of two qualitative variables

Question 9

A scatter plot is used to:

Accepted Answer

Examine the relationship between two quantitative variables

Question 10

In a Pareto chart, the categories are arranged in which order?

Accepted Answer

Descending order of frequency

Question 11

A survey of 1,145 people asked them to rate the quality of care in an emergency room as Very Good (527), Good (492), Poor (80), or Very Poor (46). What percentage rated the care as Good?

Use the formula: $$	ext{Percentage} = \frac{	ext{Frequency}}{	ext{Total}} 	imes 100$$

Accepted Answer

$$\frac{492}{1145} 	imes 100 \approx 43\%$$

Question 12

Which of the following Excel functions can be used to construct a frequency distribution from raw data?

Accepted Answer

=FREQUENCY()

Question 13

A stem-and-leaf display differs from a histogram in that:

Accepted Answer

It preserves the original data values

Question 14

A company wants to compare the unemployment rates in five states for 2011 and 2012. Which chart is most appropriate?

Accepted Answer

Clustered bar chart

Question 15

If a histogram is right-skewed, what does this indicate about the data?

Accepted Answer

Most data values are concentrated on the left side

Question 16

Which of the following best describes the main objective of a line chart?

Accepted Answer

To show the change in the value of a variable over time

Question 17

A contingency table for gender (male/female) and payment method (cash/credit/debit) shows that 7 out of 20 customers paid by cash. What is the relative frequency of cash payments?

Accepted Answer

$$\frac{7}{20} = 0.35$$

Question 18

Which of the following is a key advantage of using relative frequencies instead of absolute frequencies when comparing data from two different groups?

Accepted Answer

Relative frequencies allow for comparison regardless of group size

Question 19

A scatter plot of household size (x-axis) and monthly food cost (y-axis) shows an upward trend. What does this indicate?

Accepted Answer

As household size increases, monthly food cost increases

Question 20

Which of the following best describes the purpose of a Pareto chart in quality control?

Accepted Answer

To identify the most significant factors in a set of categories

Displaying Descriptive Statistics: Study Notes for Business Statistics II

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