Question 1

A clinical trial tests a new medication for reducing blood pressure. The results show a statistically significant reduction in blood pressure, but the average reduction is only 1 mmHg. Which of the following best describes this result?

Accepted Answer

The result is statistically significant but not practically significant because the reduction is too small to have real-world impact.

Question 2

A researcher wants to know if there is a difference in average test scores between two schools. She collects data from 30 students at each school. What type of statistical analysis is most appropriate?

Accepted Answer

A two-sample t-test, because the samples are independent.

Question 3

A study finds that the average height of a sample of 100 adult men is 175 cm. Which of the following best describes this value?

Accepted Answer

It is a statistic because it describes a characteristic of a sample.

Question 4

Which of the following is an example of data measured at the ordinal level?

Accepted Answer

Ranking of movies from best to worst.

Question 5

A hospital collects the blood types (A, B, AB, O) of its patients. What is the level of measurement for this data?

Accepted Answer

Nominal

Question 6

A sample of 50 cars is selected from a city to estimate the average fuel efficiency of all cars in the city. What is the population in this scenario?

Accepted Answer

All cars in the city.

Question 7

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

Accepted Answer

Correlation analysis

Question 8

A data set contains the following values: 2, 4, 4, 6, 8. What is the median?

Accepted Answer

$4$

Question 9

Which of the following best describes the mean?

Accepted Answer

The sum of all values divided by the number of values.

Question 10

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

$z = \frac{60 - 50}{5} = 2$

Question 11

A survey asks respondents to indicate their favorite color. What type of variable is 'favorite color'?

Accepted Answer

Qualitative, nominal

Question 12

A researcher finds a correlation coefficient of $r = 0.85$ between hours of exercise per week and resting heart rate. What does this indicate?

Accepted Answer

A strong negative linear relationship

Question 13

Which of the following is NOT a measure of center?

Accepted Answer

Range

Question 14

A data set has the following values: 10, 12, 14, 16, 18. What is the range?

Accepted Answer

$18 - 10 = 8$

Question 15

A study reports that the average salary of all employees at a company is $60,000. Is this value a statistic or a parameter?

Accepted Answer

Parameter, because it describes a population.

Question 16

Which of the following is an example of continuous data?

Accepted Answer

Height of students in centimeters.

Question 17

A sample of 5 students has test scores: 70, 80, 90, 100, 110. What is the sample variance?

Accepted Answer

$s^2 = \frac{(70-90)^2 + (80-90)^2 + (90-90)^2 + (100-90)^2 + (110-90)^2}{5-1} = 250$

Question 18

A data set contains the following values: 5, 7, 7, 8, 10. What is the mode?

Accepted Answer

$7$

Question 19

Which of the following best describes the difference between descriptive and inferential statistics?

Accepted Answer

Descriptive statistics summarize data; inferential statistics draw conclusions about populations from samples.

Question 20

A researcher wants to estimate the average number of hours college students sleep per night. She randomly selects 200 students from a university. What type of sampling method is this?

Accepted Answer

Simple random sampling

Fundamental Concepts and Applications in Introductory Statistics

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