$$ CV = \frac{4}{20} \times 100 = 20\% $$

$$ \mu = n \times p = 10 \times 0.3 = 3 $$

Question 1

Which of the following best describes the main purpose of statistics?

Accepted Answer

To collect, organize, summarize, and interpret data to aid in making informed decisions.

Question 2

Which of the following is an example of qualitative data?

Accepted Answer

The color of cars in a parking lot

Question 3

A researcher records the heights of 100 students. What type of variable is 'height'?

Accepted Answer

Quantitative, continuous

Question 4

Which level of measurement is appropriate for the variable 'marital status' (single, married, divorced)?

Accepted Answer

Nominal

Question 5

Which of the following is a limitation of statistics?

Accepted Answer

It does not reveal the entire study of a problem.

Question 6

Given the following data: 2, 4, 6, 8, 10. What is the mean?

Accepted Answer

$$ \frac{2+4+6+8+10}{5} = 6 $$

Question 7

Which of the following is the correct formula for the variance of a population?

Accepted Answer

$$ \$$sigma^2$$ = \frac{\sum (x_i - \mu)^2$}{N} $$

Question 8

A frequency distribution table is most useful for which of the following?

Accepted Answer

Summarizing large sets of data into classes and frequencies.

Question 9

Which graphical method is best for displaying the distribution of a continuous variable?

Accepted Answer

Histogram

Question 10

If the mean of a data set is 20 and the standard deviation is 4, what is the coefficient of variation (CV)?

Accepted Answer

$$ CV = \frac{4}{20} 	imes 100 = 20\% $$

Question 11

Which of the following is NOT a measure of central tendency?

Accepted Answer

Range

Question 12

A researcher wants to know if there is a relationship between hours studied and exam scores. Which statistical method should be used?

Accepted Answer

Correlation analysis

Question 13

Which of the following statements about the binomial distribution is correct?

Accepted Answer

Each trial is independent and has only two possible outcomes.

Question 14

Given a binomial distribution with $$ n = 10 $$ and $$ p = 0.3 $$, what is the mean?

Accepted Answer

$$ \mu = n 	imes p = 10 	imes 0.3 = 3 $$

Question 15

Which of the following is a property of the normal distribution?

Accepted Answer

It is symmetric about the mean.

Question 16

A survey is conducted to estimate the average income of households in a city. What type of data collection method is this?

Accepted Answer

Survey

Question 17

Which of the following is the correct formula for the standard deviation of a sample?

Accepted Answer

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

Question 18

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

Accepted Answer

Number of rooms in a house

Question 19

Which of the following best describes the difference between primary and secondary data?

Accepted Answer

Primary data is collected directly by the researcher, while secondary data is collected by someone else.

Question 20

Which of the following is the correct formula for the range of a data set?

Accepted Answer

$$ 	ext{Range} = X_{	ext{max}} - X_{	ext{min}} $$

STA 2260: Statistics – Mini-Textbook Study Notes (Chapters 1 & 2)

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