Question 1

Which of the following best describes the difference between a parameter and a statistic?

Accepted Answer

A parameter is a numerical summary of a population, while a statistic is a numerical summary of a sample.

Question 2

A pharmaceutical company wants to test a new drug. They randomly assign 100 patients to receive the drug and 100 patients to receive a placebo. Which type of study is this?

Accepted Answer

Experimental study

Question 3

Which of the following is a discrete variable?

Accepted Answer

The number of cars in a parking lot

Question 4

A researcher collects data on the favorite ice cream flavors of 200 students. What type of variable is 'ice cream flavor'?

Accepted Answer

Qualitative (categorical)

Question 5

Which sampling method is used when every member of the population has an equal chance of being selected?

Accepted Answer

Simple random sampling

Question 6

Given the following data set: 2, 4, 4, 6, 8. What is the median?

Accepted Answer

$$4$$

Question 7

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

Accepted Answer

Range

Question 8

If a distribution is skewed to the right, which of the following is true?

Accepted Answer

Mean \u003e Median \u003e Mode

Question 9

A boxplot is useful for displaying which of the following?

Accepted Answer

The five-number summary: minimum, first quartile, median, third quartile, maximum

Question 10

Which formula correctly calculates the sample variance $$s^2$$ for a data set with $$n$$ observations and sample mean $$\overline{x}$$?

Accepted Answer

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

Question 11

A hospital administrator wants to compare the average length of stay for patients in two different wards. Which graphical display is most appropriate?

Accepted Answer

Side-by-side boxplots

Question 12

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

Accepted Answer

Blood type (A, B, AB, O)

Question 13

If the probability of rain tomorrow is $$0.3$$, what is the probability that it will NOT rain?

Accepted Answer

$$0.7$$

Question 14

Which of the following best describes the empirical rule for a normal distribution?

Accepted Answer

All of the above.

Question 15

A researcher wants to estimate the average cholesterol level of adults in a city. She divides the city into neighborhoods and randomly selects some neighborhoods, then surveys all adults in those neighborhoods. What sampling method is this?

Accepted Answer

Cluster sampling

Question 16

Which of the following is the correct formula for the z-score of a value $$x in a $$data set with mean $$\mu$$ and standard deviation $$\sigma$$?

Accepted Answer

$$z = \frac{x - \mu}{\sigma}$$

Question 17

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

$$z = 1$$

Question 18

Which of the following is NOT a characteristic of a normal distribution?

Accepted Answer

It is skewed to the right.

Question 19

Which of the following best describes a conditional distribution?

Accepted Answer

A distribution of one variable for individuals who satisfy some condition on another variable.

Question 20

A company wants to know if there is a relationship between employee job satisfaction (measured on a scale from 1 to 10) and salary. Which graphical display is most appropriate?

Accepted Answer

Scatterplot

Midterm 1 Study Guide: Introductory Statistics Concepts and Skills

Guida di studio - Domande di pratica

Study guide - Flashcard