Question 1

Which of the following best describes the difference between descriptive and inferential statistics?

Accepted Answer

Descriptive statistics summarize and organize data, while inferential statistics use sample data to make generalizations about a population.

Question 2

A researcher collects data on the number of hours students study per week. Which level of measurement is most appropriate for this variable?

Accepted Answer

Ratio

Question 3

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

Accepted Answer

Variance

Question 4

A hospital administrator wants to compare the average recovery time for two different treatments. Which statistical method should be used?

Accepted Answer

Hypothesis test for two samples

Question 5

If the probability of a patient recovering from a disease after treatment is $$0.8$$, what is the probability that two patients both recover, assuming independence?

Accepted Answer

$$0.64$$

Question 6

Which formula correctly calculates the variance of a discrete probability distribution?

Accepted Answer

$$\sum (x_i - \mu)^2$ P(x_i)$$

Question 7

A company wants to test if the mean salary of its employees is different from the industry average. Which hypothesis test should be used?

Accepted Answer

One-sample hypothesis test

Question 8

In a normal distribution, approximately what percentage of data falls within one standard deviation of the mean?

Accepted Answer

68%

Question 9

Which of the following is the correct formula for the linear regression equation?

Accepted Answer

$$y = a + bx$$

Question 10

A psychologist wants to determine if there is a relationship between stress level and hours of sleep. Which statistical method is most appropriate?

Accepted Answer

Linear correlation

Question 11

Which of the following statements about the binomial distribution is TRUE?

Accepted Answer

It requires a fixed number of independent trials, each with the same probability of success.

Question 12

A school administrator wants to test if the distribution of students across majors is as expected. Which statistical test should be used?

Accepted Answer

Chi-square test for goodness of fit

Question 13

Which formula represents Bayes’ Theorem?

Accepted Answer

$$P(A|B) = \frac{P(B|A)P(A)}{P(B)}$$

Question 14

A scientist wants to compare the mean growth rates of three different plant fertilizers. Which statistical method should be used?

Accepted Answer

ANOVA

Question 15

Which of the following best describes a p-value in hypothesis testing?

Accepted Answer

The probability of obtaining a result at least as extreme as the observed result, assuming the null hypothesis is true.

Question 16

A medical researcher is testing a new drug. The null hypothesis is that the drug has no effect. If the researcher rejects the null hypothesis, what does this mean?

Accepted Answer

There is sufficient evidence to suggest the drug has an effect.

Question 17

Which formula is used to calculate the sample mean?

Accepted Answer

$$\bar{x} = \frac{\sum x_i}{n}$$

Question 18

A social scientist wants to determine if there is an association between gender and voting preference. Which statistical test should be used?

Accepted Answer

Chi-square test for independence

Question 19

Which of the following is a non-parametric statistical method?

Accepted Answer

Wilcoxon rank-sum test

Question 20

A business analyst uses a scatterplot to visualize the relationship between advertising spending and sales. Which statistical concept is being illustrated?

Accepted Answer

Correlation

Porterville College MATH 122: Introduction to Probability and Statistics – Syllabus and Course Structure Study Guide

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