Question 1

Which of the following best describes the Central Limit Theorem and its importance in inferential statistics?

Accepted Answer

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

Question 2

A pharmaceutical company wants to test if a new drug lowers blood pressure more effectively than the current standard. Which statistical test should they use to compare the means of two independent groups?

Accepted Answer

Two-sample t-test

Question 3

Given a data set, which of the following is NOT a measure of central tendency?

Accepted Answer

Standard deviation

Question 4

Suppose you roll a fair six-sided die. What is the probability of rolling a number greater than 4?

Accepted Answer

$$P = \frac{2}{6}$$

Question 5

Which formula correctly represents the confidence interval for a population mean when the population standard deviation is known?

Accepted Answer

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

Question 6

A researcher wants to test if the average commute time in a city is different from 30 minutes. What is the null hypothesis ($$H_0) $$for this test?

Accepted Answer

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

Question 7

Which of the following statements about Type I and Type II errors is correct?

Accepted Answer

Type I error is rejecting a true null hypothesis; Type II error is failing to reject a false null hypothesis.

Question 8

Which equation represents the linear regression line for predicting $$y$$ from $$x$$?

Accepted Answer

$$y = a + bx$$

Question 9

A study finds a correlation coefficient $$r = 0.85$$ between hours studied and exam scores. What does this indicate?

Accepted Answer

There is a strong positive linear relationship between hours studied and exam scores.

Question 10

Which of the following is a requirement for using the one-way ANOVA test?

Accepted Answer

The populations must have equal variances.

Question 11

A hospital administrator wants to know if there is an association between gender (male/female) and preference for a new hospital service (yes/no). Which statistical test should be used?

Accepted Answer

Chi-square test for independence

Question 12

Which formula is used to calculate the sample variance $$s^2$$ for a data set with $$n$$ observations and sample mean $$\bar{x}$$?

Accepted Answer

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

Question 13

If a 95% confidence interval for a population mean is $$(12, 18)$$, which of the following statements is correct?

Accepted Answer

We are 95% confident that the population mean is between 12 and 18.

Question 14

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

Accepted Answer

It is skewed to the right.

Question 15

A quality control manager wants to estimate the proportion of defective items in a large shipment. Which formula should be used for the confidence interval for a population proportion $$p$$?

Accepted Answer

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

Question 16

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

Accepted Answer

Failing to reject a false null hypothesis

Question 17

A researcher collects data on the number of hours students study and their final exam scores. Which statistical method should be used to predict exam scores based on hours studied?

Accepted Answer

Simple linear regression

Question 18

Which of the following is an example of a discrete probability distribution?

Accepted Answer

Binomial distribution

Question 19

Which of the following is a correct interpretation of a $$p-$$value in hypothesis testing?

Accepted Answer

The probability of obtaining a result as extreme or more extreme than the observed result, assuming the null hypothesis is true.

Question 20

A teacher wants to compare the average test scores of three different teaching methods. Which statistical test should be used?

Accepted Answer

One-way ANOVA

Elementary Statistics (STAT C1000) Syllabus and Course Overview

Guida di studio - Domande di pratica

Study guide - Flashcard