Question 1

Which of the following best describes the four elements of a descriptive statistics problem?

Accepted Answer

Population/sample, variables, summary tools, identification of patterns

Question 2

A researcher wants to study the effect of a new fertilizer on plant growth. She randomly assigns plants to two groups: one receives the new fertilizer, the other does not. Which method of data collection is being used?

Accepted Answer

Designed experiment

Question 3

Which of the following variables is qualitative?

Accepted Answer

Location (e.g., 'Florida', 'Georgia')

Question 4

Why is a representative sample essential for inferential statistics?

Accepted Answer

It allows for accurate inferences about the population

Question 5

A survey is conducted by randomly calling listed phone numbers to ask about political opinions. Which of the following is a potential issue with this sampling method?

Accepted Answer

It may exclude people without phones or those unavailable at certain times

Question 6

Which of the following best describes a process in statistics?

Accepted Answer

A series of actions or operations that transform inputs to outputs

Question 7

A researcher collects data on bridge conditions, recording 'good', 'fair', or 'poor'. What type of data is this?

Accepted Answer

Nominal qualitative

Question 8

Which of the following is an example of a variable measured in an observational study?

Accepted Answer

DQ value of firms from annual balance sheets

Question 9

A company wants to estimate the mean speed of deliveries to all its customers. It sends surveys to a subset of customers. Which statistical approach is being used?

Accepted Answer

Inferential statistics

Question 10

Which of the following is a quantitative variable?

Accepted Answer

Average daily traffic (e.g., 3,579 vehicles)

Question 11

A survey asks respondents to rate their agreement with a statement on a scale from 1 (strongly disagree) to 5 (strongly agree). What type of data is produced?

Accepted Answer

Ordinal qualitative

Question 12

Suppose you want to select a random sample of 900 intersections from a city grid of 500 rows and 1,000 columns. Which sampling method is described by randomly selecting rows and columns and pairing them?

Accepted Answer

Random sampling using row-column combinations

Question 13

A study collects data from all U.S. Treasury records in 1861 to describe its financial condition. What type of statistical study is this?

Accepted Answer

Descriptive study

Question 14

Which of the following is a potential problem when using survey data to make inferences about a population?

Accepted Answer

Survey respondents may not be representative of the population

Question 15

A researcher wants to estimate the proportion of all U.S. residents who believe the president is doing a good job. Which formula would be used to estimate this proportion from a sample?

Accepted Answer

$$ \hat{p} = \frac{x}{n} $$

Question 16

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

Accepted Answer

A sample is a subset of a population

Question 17

A study measures job satisfaction scores (numerical values) and gender ('male', 'female') among accounting alumni. Which statement is correct?

Accepted Answer

Job satisfaction is quantitative, gender is qualitative

Question 18

In a designed experiment, college students are randomly assigned to two groups to test recycling rates. Which is the experimental unit?

Accepted Answer

The college student

Question 19

Which of the following is an example of a variable that is measured on a ratio scale?

Accepted Answer

Income (e.g., $50,000)

Question 20

A company uses the mean speed of deliveries from a sample to estimate the mean speed for all customers. Which formula represents the sample mean?

Accepted Answer

$$ \bar{x} = \frac{\sum x_i}{n} $$

Statistics, Data, and Statistical Thinking: Structured Study Notes

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