Question 1

Which of the following best describes the difference between a population and a sample in statistics?

Accepted Answer

A population is the entire group of interest, while a sample is a subset selected for study.

Question 2

A researcher wants to estimate the average height of all university students. She randomly selects 100 students from the university. Which type of statistics is she using to make conclusions about all students based on her sample?

Accepted Answer

Inferential statistics

Question 3

Which sampling method involves dividing the population into groups based on a characteristic, then randomly selecting some groups and including all members of those groups in the sample?

Accepted Answer

Cluster sampling

Question 4

Suppose you have a list of 1,000 patients and you select every 10th patient for your sample. Which sampling method are you using?

Accepted Answer

Systematic sampling

Question 5

If a variable can only take on specific, separate values (such as the number of cars in a parking lot), it is best described as:

Accepted Answer

Discrete quantitative

Question 6

Which of the following is an example of a qualitative variable?

Accepted Answer

The color of a car

Question 7

A stem-and-leaf plot is most useful for:

Accepted Answer

Showing the distribution and shape of quantitative data

Question 8

Given a histogram of exam scores that is skewed to the left, which statement is most accurate?

Accepted Answer

Most students scored high, with a few low scores.

Question 9

If the relative frequency of students who received an 'A' in a class is 0.2, and there are 50 students, how many students received an 'A'?

$$	ext{Number of students} = 	ext{Relative frequency} 	imes 	ext{Total students}$$

Accepted Answer

10

Question 10

A dotplot is constructed for the number of daily visitors to a website over 30 days. What can you infer if the dotplot shows most dots clustered on the right side with a few dots trailing to the left?

Accepted Answer

The data is left-skewed.

Question 11

Which of the following best describes a simple random sample?

Accepted Answer

Every member of the population has an equal chance of being selected.

Question 12

A hospital wants to compare satisfaction levels between male and female patients. They randomly select 50 males and 50 females. Which sampling method is used?

Accepted Answer

Stratified sampling

Question 13

Which of the following variables is continuous quantitative?

Accepted Answer

The height of a person in centimeters

Question 14

If a histogram of household incomes is right-skewed, which of the following is most likely true?

Accepted Answer

Most households have low incomes, with a few very high incomes.

Question 15

A frequency table shows the number of accidents at an intersection each month: 0, 1, 2, 3, 4. Which type of variable is 'number of accidents'?

Accepted Answer

Discrete quantitative

Question 16

A researcher wants to study the effect of a new drug. She divides patients into age groups and randomly selects equal numbers from each group. Which sampling method is she using?

Accepted Answer

Stratified sampling

Question 17

Which of the following statements about descriptive statistics is correct?

Accepted Answer

Descriptive statistics summarize and describe features of a data set.

Question 18

A company wants to estimate the proportion of defective products. If the chance of selecting a specific sample of 5 products from a batch of 100 is $$\frac{1}{\binom{100}{5}}$$, which sampling method is being used?

Accepted Answer

Simple random sampling

Question 19

Which of the following best describes a symmetric distribution?

Accepted Answer

The left and right sides of the distribution are mirror images.

Question 20

A researcher records the time (in seconds) it takes for a chemical reaction to complete. Which type of variable is this?

Accepted Answer

Continuous quantitative

Introductory Statistics: Sampling, Data Types, and Data Visualization

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