Q: A student randomly selects a card from a standard deck. What is the probability that the card is either a heart or a king?

$$P(\text{heart or king}) = \frac{13}{52} + \frac{4}{52} - \frac{1}{52} = \frac{16}{52}$$

Q: If two events $$A$$ and $$B$$ are independent, which equation must be true?

$$P(A \text{ and } B) = P(A) \times P(B)$$

Question 1

A researcher wants to study the effect of a new drug on blood pressure. She randomly assigns participants to either receive the drug or a placebo and measures their blood pressure after 4 weeks. Which type of study is this?

Accepted Answer

Experiment

Question 2

Which of the following best describes a parameter?

Accepted Answer

A characteristic of a population

Question 3

A survey asks students to report their favorite color. What type of variable is 'favorite color'?

Accepted Answer

Categorical variable

Question 4

Which of the following is most appropriate for displaying the distribution of a categorical variable?

Accepted Answer

Bar graph

Question 5

A data set has the following values: 2, 4, 4, 4, 5, 6, 100. Which measure of central tendency is most affected by the outlier?

Accepted Answer

Mean

Question 6

Given a bell-shaped distribution with mean $$\mu = 50$$ and standard deviation $$\sigma = 5$$, what percentage of data falls within the interval $$[40, 60]$$?

Accepted Answer

$$68\%$$

Question 7

A student scored 85 on a test where the mean was 80 and the standard deviation was 5. What is the student's z-score?

Accepted Answer

$$z = \frac{85 - 80}{5} = 1$$

Question 8

Which of the following is NOT part of the five-number summary?

Accepted Answer

Mean

Question 9

If the probability of event $$A is$$ $$0.3$$ and the probability of event $$B is$$ $$0.5$$, and $$A$$ and $$B$$ are disjoint, what is $$P(A 	ext{ or } B)$$?

Accepted Answer

$$P(A 	ext{ or } B) = 0.8$$

Question 10

A fair six-sided die is rolled. What is the probability of rolling at least one '6' in two rolls?

Accepted Answer

$$1 - (\frac{5}{6})^2$ = \frac{11}{36}$$

Question 11

Which of the following statements about probability models is TRUE?

Accepted Answer

The sum of all probabilities in the sample space must equal $$1$$

Question 12

A boxplot shows a distribution with a long right whisker and the median closer to the left. What is the shape of the distribution?

Accepted Answer

Right-skewed

Question 13

A hospital records the number of patients admitted each day. What type of variable is 'number of patients admitted'?

Accepted Answer

Discrete numerical variable

Question 14

If the range of a data set increases due to an extreme value, which measure of dispersion is LEAST affected?

Accepted Answer

Interquartile range (IQR)

Question 15

In a probability experiment, the sample space consists of three outcomes: $$A$$, $$B$$, and $$C. If$$ $$P(A) = 0.2$$ and $$P(B) = 0.5$$, what must $$P(C) be to $$satisfy the requirements of a probability model?

Accepted Answer

$$P(C) = 0.3$$

Question 16

A student randomly selects a card from a standard deck. What is the probability that the card is either a heart or a king?

Accepted Answer

$$P(	ext{heart or king}) = \frac{13}{52} + \frac{4}{52} - \frac{1}{52} = \frac{16}{52}$$

Question 17

If two events $$A$$ and $$B$$ are independent, which equation must be true?

Accepted Answer

$$P(A 	ext{ and } B) = P(A) 	imes P(B)$$

Question 18

A data set has quartiles $$Q_1 = 20$, Q_3$ = 40. $$What is the interquartile range (IQR)?

Accepted Answer

$$IQR = Q_3$ - Q_1$ = 20$$

Question 19

A researcher wants to determine if smoking is associated with lung cancer. She collects data from smokers and non-smokers and records whether they have lung cancer. Which type of study is this?

Accepted Answer

Observational study

Introductory Statistics: Study Guide for Midterm 1 (Chapters 1, 2, 3, 5)

Study Guide - Practice Questions

Study Guide - Flashcards