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

The company randomly assigns patients to receive either the new drug or a placebo and compares outcomes.

Question 3

Which of the following is an example of bias in sampling?

Accepted Answer

Selecting survey participants only from a single neighborhood when studying city-wide opinions.

Question 4

Given a dataset with the following values: 2, 4, 4, 6, 8, what is the mean?

Accepted Answer

$$ \frac{2 + 4 + 4 + 6 + 8}{5} = 4.8 $$

Question 5

Which of the following is the correct formula for the standard deviation of a population?

Accepted Answer

$$ \sigma = \sqrt{\frac{\sum (x_i - \mu)^2$}{N}} $$

Question 6

A boxplot is used to display which of the following?

Accepted Answer

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

Question 7

Which of the following statements about the Central Limit Theorem is correct?

Accepted Answer

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

Question 8

If the probability of event A is $$0.3$$ and the probability of event B is $$0.5$$, and A and B are independent, what is the probability that both A and B occur?

Accepted Answer

$$ 0.3 	imes 0.5 = 0.15 $$

Question 9

Which of the following is the correct formula for a confidence interval for a population mean when the population standard deviation is known?

Accepted Answer

$$ \bar{x} \pm z^* \frac{\sigma}{\sqrt{n}} $$

Question 10

A researcher wants to test if a new teaching method improves test scores. Which is the correct null hypothesis for this scenario?

Accepted Answer

$$ H_0$: \mu = \mu_0$ $$

Question 11

Which of the following best describes a Type I error in hypothesis testing?

Accepted Answer

Rejecting the null hypothesis when it is actually true.

Question 12

A hospital administrator wants to estimate the proportion of patients satisfied with their service. Which formula should be used to estimate the confidence interval for a population proportion?

Accepted Answer

$$ \hat{p} \pm z^* \sqrt{\frac{\hat{p}(1-\hat{p})}{n}} $$

Question 13

Which of the following is the correct formula for the correlation coefficient $$r$$?

Accepted Answer

$$ r = \frac{\sum (x_i - \bar{x})(y_i - \bar{y})}{\sqrt{\sum (x_i - \bar{x})^2$ \sum (y_i - \bar{y})^2$}} $$

Question 14

A fair coin is flipped 10 times. What is the probability of getting exactly 5 heads? (Use the binomial probability formula.)

Accepted Answer

$$ P(X = 5) = {10 \choose 5} (0.5)^5$ (0.5)^5$ $$

Question 15

Which of the following best describes an observational study?

Accepted Answer

Researchers observe subjects without manipulating any variables.

Question 16

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

Accepted Answer

Range

Question 17

A scatter diagram is most useful for which of the following?

Accepted Answer

Visualizing the relationship between two quantitative variables.

Question 18

Which of the following is the correct formula for the least squares regression line?

Accepted Answer

$$ \hat{y} = b_0$ + b_1$ x $$

Elementary Statistical Methods (MATH 1342) Syllabus and Course Overview

스터디 가이드 - 연습 문제

학습 가이드 - 플래시카드