$$\text{Class Midpoint} = \frac{\text{Lower Class Limit} + \text{Upper Class Limit}}{2}$$

Question 1

Which of the following is an example of a quantitative, discrete variable?

Accepted Answer

Number of daily admissions to a hospital

Question 2

A researcher records the blood pressure of patients in mmHg. What type of variable is blood pressure?

Accepted Answer

Quantitative, continuous

Question 3

Which scale of measurement allows for meaningful differences and has a true zero point?

Accepted Answer

Ratio scale

Question 4

A pain score scale (0, 2, 4, 6, 8, 10) is best classified as which type of variable?

Accepted Answer

Qualitative, ordinal

Question 5

Which measure of central tendency is most appropriate for describing the center of a highly skewed distribution?

Accepted Answer

Median

Question 6

Given the following data set: 10, 29, 0, 5, 100, what is the mean?

Accepted Answer

$$\frac{10+29+0+5+100}{5} = 28.8$$

Question 7

Which of the following best describes a histogram?

Accepted Answer

A graph consisting of bars representing classes of quantitative data, with bar heights showing frequency or relative frequency.

Question 8

If a distribution is right-skewed, which of the following is true?

Accepted Answer

Median \u003c Mean

Question 9

What is the formula for the sample standard deviation $$s$$?

Accepted Answer

$$s = \sqrt{\frac{\sum_{i=1}^{n}(x_i - \bar{x})^2$}{n-1}}$$

Question 10

A box-and-whisker plot is most useful for displaying which of the following?

Accepted Answer

The median, quartiles, and potential outliers

Question 11

Which of the following is NOT a measure of dispersion?

Accepted Answer

Median

Question 12

Given a dataset: 6, 17, 17, 17, 18, 18, 19, 23, what is the interquartile range (IQR)?

Accepted Answer

$$IQR = Q_3$ - Q_1$ = 18.5 - 17 = 1.5$$

Question 13

Which of the following statements about parameters and statistics is correct?

Accepted Answer

A parameter is a descriptive measure computed from a population and is fixed.

Question 14

A frequency distribution table must have which property?

Accepted Answer

All frequencies must add up to the total sample size.

Question 15

Which of the following is a real-world example of a qualitative, nominal variable?

Accepted Answer

Eye color (black, amber, blue, brown)

Question 16

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

Accepted Answer

$$	ext{Class Midpoint} = \frac{	ext{Lower Class Limit} + 	ext{Upper Class Limit}}{2}$$

Question 17

Which of the following is true about the mode?

Accepted Answer

It is the value that occurs most frequently in a dataset.

Question 18

A hospital administrator wants to summarize the number of daily admissions. Which graphical display is most appropriate?

Accepted Answer

Histogram

Question 19

Which of the following best describes the difference between interval and ratio scales?

Accepted Answer

Ratio scales have a true zero point, while interval scales do not.

Descriptive Statistics & Data Visualization: Study Notes

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