Question 1

Which of the following best describes the primary purpose of statistics in scientific research?

Accepted Answer

To collect, analyze, present, and interpret data in order to reach reasonable conclusions.

Question 2

A pharmaceutical company wants to test a new drug. Which of the following best describes a designed experiment?

Accepted Answer

Researchers assign participants randomly to either the drug or placebo group and compare outcomes.

Question 3

Which of the following sampling methods is most likely to produce a representative sample?

Accepted Answer

Simple random sampling

Question 4

A news outlet reports that 70% of its readers support a new policy, but only surveyed people who visited their website. What type of bias is most likely present?

Accepted Answer

Sampling bias

Question 5

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

Accepted Answer

Standard deviation

Question 6

Given the following data set representing the number of books read by 5 students in a month: 2, 4, 4, 6, 8. What is the median?

Accepted Answer

$$4$$

Question 7

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

Accepted Answer

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

Question 8

A boxplot is useful for which of the following purposes?

Accepted Answer

Identifying outliers and visualizing the five-number summary

Question 9

Which of the following statements about the correlation coefficient $$r is $$TRUE?

Accepted Answer

$$r$$ ranges from $$-1 to$$ $$1$$ and measures the strength and direction of a linear relationship.

Question 10

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

Accepted Answer

$$0.7$$

Question 11

A fair six-sided die is rolled. What is the probability of rolling an even number?

Accepted Answer

$$\frac{3}{6}$$

Question 12

Which formula represents the binomial probability of getting exactly $$k$$ successes in $$n$$ independent trials with probability $$p of $$success?

Accepted Answer

$$P(X = k) = {n \choose k} p^k (1-p$$)^{n-k}$$

Question 13

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

Accepted Answer

It is symmetric about the mean.

Question 14

If a population has mean $$\mu = 50$$ and standard deviation $$\sigma = 10$$, what is the standard error of the mean for samples of size $$n = 25$$?

Accepted Answer

$$2$$

Question 15

A 95% confidence interval for a population mean is calculated as $$(45, 55). $$What does this mean?

Accepted Answer

We are 95% confident that the population mean lies between 45 and 55.

Question 16

Which of the following is the correct null hypothesis for testing if the average commute time in a city is 30 minutes?

Accepted Answer

$$H_0$$: \mu = 30$$

Question 17

Which of the following best describes the Central Limit Theorem?

Accepted Answer

The sampling distribution of the sample mean approaches a normal distribution as the sample size increases, regardless of the population's distribution.

Question 18

A researcher wants to test if a new teaching method improves test scores. Which statistical method should be used to compare the mean scores of two independent groups?

Accepted Answer

Two-sample $$t-$$test

Question 19

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

Accepted Answer

The number of cars passing through an intersection in an hour

Question 20

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

Accepted Answer

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

Elementary Statistical Methods (MATH 1342) – Syllabus and Course Structure

Guida di studio - Domande di pratica

Study guide - Flashcard