Question 1

Which of the following best describes a parameter in statistics?

Accepted Answer

A numerical value that describes a characteristic of a population.

Question 2

A researcher records the number of cars passing through an intersection each hour. Which type of data is this?

Accepted Answer

Discrete data

Question 3

A hospital records the blood types (A, B, AB, O) of its patients. Which level of measurement is this?

Accepted Answer

Nominal

Question 4

Which of the following best differentiates an observational study from an experiment?

Accepted Answer

In an experiment, the researcher manipulates one or more variables; in an observational study, the researcher does not.

Question 5

A company wants to survey its employees by selecting every 10th person from an alphabetical list. Which sampling method is being used?

Accepted Answer

Systematic sampling

Question 6

A study follows a group of patients over 10 years to observe the development of heart disease. What type of observational study is this?

Accepted Answer

Prospective

Question 7

Which of the following is NOT a characteristic of a histogram?

Accepted Answer

It is used for categorical data.

Question 8

Given the following data set: $$3, 7, 7, 9, 10, 12, 15$$, what is the median?

Accepted Answer

$$9$$

Question 9

Which of the following best describes a pie chart?

Accepted Answer

A circular graph divided into sectors representing categories.

Question 10

A teacher records the test scores of her class: $$60, 70, 80, 90, 100. $$What is the range of the data?

Accepted Answer

$$40$$

Question 11

Given the frequency distribution below, what is the mean?

Class: $$1-3 ($$Frequency: $$2$$), $$4-6 ($$Frequency: $$3$$), $$7-9 ($$Frequency: $$5)

$$Use the class midpoints for calculation.

Accepted Answer

$$6.2$$

Question 12

A data set has a mean of $$50$$ and a standard deviation of $$5. $$What is the z-score for a value of $$60$$?

Accepted Answer

$$2$$

Question 13

Which of the following is the correct formula for the weighted mean $$\bar{x}_w$$?

Accepted Answer

$$\bar{x}_w = \frac{\sum w_i x_i}{\sum w_i}$$

Question 14

A set of exam scores has a mean of $$75$$ and a standard deviation of $$8. $$According to Chebyshev's theorem, at least what percentage of the data falls within $$k=2$$ standard deviations of the mean?

Accepted Answer

$$75\%$$

Question 15

Which of the following is NOT a step in constructing a frequency distribution?

Accepted Answer

Calculating the mean of the data.

Question 16

A researcher wants to compare the average income of people in two different cities. Which type of graph would be most appropriate?

Accepted Answer

Bar chart

Question 17

Given the data set $$2, 4, 4, 4, 5, 5, 7, 9$$, what is the mode?

Accepted Answer

$$4$$

Question 18

A sample of weights (in kg) is: $$60, 62, 65, 68, 70. $$What is the variance of the sample? (Round to the nearest tenth)

Accepted Answer

$$15.5$$

Question 19

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

Accepted Answer

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

Question 20

A data set has the following five-number summary: $$10, 20, 30, 40, 50. $$What is the interquartile range (IQR)?

Accepted Answer

$$20$$

Fundamental Concepts and Methods in Statistics: Study Guide

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