Statistics Exam 1 Review

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to Lesson

Podcast

Play an AI-generated podcast conversation about this lesson
Download our mobile app to listen on the go
Get App

Questions and Answers

Which of the following statements best describes how variance relates to standard deviation?

  • Variance and standard deviation are unrelated measures of dispersion.
  • Variance is the square root of the standard deviation.
  • Standard deviation is the inverse of the variance.
  • Standard deviation is the square root of the variance. (correct)

Events A, B, and C are collectively exhaustive. Which of the following statements must be true?

  • The union of A, B, and C covers the entire sample space. (correct)
  • Events A, B, and C must be independent.
  • The intersection of A, B, and C must be empty.
  • The probability of each event must be equal.

Given events X = {1, 3, 5} and Y = {3, 5, 7}, which of the following represents the intersection of X and Y?

  • {1}
  • {1, 3, 5, 7}
  • {}
  • {1, 7}
  • {3, 5} (correct)

The average score on an exam is 80 with a standard deviation of 5. Assuming a normal distribution, approximately what percentage of students scored between 70 and 90?

<p>95% (D)</p> Signup and view all the answers

If the covariance between two variables is 0, what can be concluded about their correlation?

<p>There is no linear correlation. (A)</p> Signup and view all the answers

A researcher is analyzing customer satisfaction scores for a particular product. They notice that a few customers have given extremely low scores, significantly lower than the majority. Which measure of central tendency will be most affected by these outlier scores?

<p>Mean (C)</p> Signup and view all the answers

In a study examining the relationship between hours of sleep and exam performance, a researcher collects data on both variables from a sample of college students. The researcher then uses this sample data to make generalizations about the entire population of college students. What type of statistical analysis is exemplified in this scenario?

<p>Inferential Statistics (A)</p> Signup and view all the answers

A company wants to visually represent the distribution of its sales across different product categories. Which graphical tool is most appropriate for displaying the relative frequency of each product category?

<p>Horizontal Bar Chart (C)</p> Signup and view all the answers

Suppose you are analyzing the prices of a particular stock over the last 5 years. This data is best described as:

<p>Time series data (D)</p> Signup and view all the answers

What is the correct notation to represent two events, A and B, as independent events?

<p>$P(A | B) = P(A)$ (B)</p> Signup and view all the answers

A researcher wants to investigate the effects of a new fertilizer on crop yield. They divide a farm into several plots, apply the fertilizer to some plots, and leave others untreated as a control. What is the population in this scenario?

<p>All possible crop yields with and without the fertilizer. (D)</p> Signup and view all the answers

A store manager finds that 60% of customers purchase coffee, 30% purchase a pastry, and 10% purchase both. Are the events 'purchasing coffee' and 'purchasing a pastry' mutually exclusive? Explain.

<p>No, because 10% of customers purchase both. (D)</p> Signup and view all the answers

A student scores 80 on a math exam. The mean score for the exam is 70, and the standard deviation is 5. What is the student's Z-score?

<p>2 (A)</p> Signup and view all the answers

Flashcards

Mutually Exclusive Events

Events that cannot occur at the same time. If one event happens, the other cannot.

Descriptive vs. Inferential Statistics

Describes data (mean, median, mode) or draws inferences (predictions, hypotheses).

Population

The entire group you want to know about.

Quantitative vs. Qualitative Data

Numerical (e.g., age) vs. Categorical (e.g., color).

Signup and view all the flashcards

Frequency

A measure of how many times a value occurs.

Signup and view all the flashcards

Outliers Influence Which Statistic the Most?

The observation most impacted by extreme values

Signup and view all the flashcards

Time Series Data

Data collected over several time periods focusing of a single variable.

Signup and view all the flashcards

Statistic

A value calculated from sample data.

Signup and view all the flashcards

Empirical Rule

Approximately 68% of data falls within 1 standard deviation of the mean, 95% within 2, and 99.7% within 3 in a normal distribution.

Signup and view all the flashcards

Dispersion

A measure of how spread out a set of data is.

Signup and view all the flashcards

Variance

The average of the squared differences from the mean. Standard deviation is the square root of variance.

Signup and view all the flashcards

Collectively Exhaustive Events

Events are collectively exhaustive if their union covers the entire sample space. At least one of the events must occur.

Signup and view all the flashcards

Union (Probability)

The set containing all elements that are in A or B or both. Notation: A ∪ B.

Signup and view all the flashcards

Study Notes

  • Exam 1 includes 40 questions to be answered in 50 minutes.
  • The exam is in person and on paper; a scantron will be provided.
  • Mutually exclusive events should be understood with examples.

Branches of Statistics

  • The two branches of statistics are: descriptive and inferential.

Independent Events Notation

  • Notation for two independent events should be understood.

Z-Score

  • A Z-score includes characteristics, formula, and calculation with given numbers.

Population vs Sample

  • Population definition including how a sample differs from a population should be understood.
  • Examples of population and its corresponding sample should be practiced.

Variable Data

  • Examples differentiating quantitative vs. qualitative variables/data should be understood.
  • Examples differentiating descriptive vs. inferential data should be understood.

Data Subset

  • Reasons for subsetting data should be understood.

Horizontal Bar Chart

  • The process of creating a horizontal bar chart should be understood.
  • The appropriate graphical tool should be used to display the relative frequency of a numerical variable.

Frequency

  • Understanding, finding, and defining frequency is key.
  • The ability to find relative frequency from a frequency table should be understood.
  • The process of finding relative frequency should be understood.
  • The difference between relative frequency and percent frequency should be understood.

Budget Allocation

  • Calculation of spending given budget percentages is relevant.
  • For instance, spending 35% of a weekly food budget with a $200 monthly budget requires calculation.

Observation Proportion

  • Determining the proportion of observations within a specified range requires calculation.
  • For example, determining the proportion of observations at least 18 but less than 24.

Statistics and Outliers

  • Recognizing the statistic most influenced by outliers is important.

Probability Calculation

  • Probability calculations involving customer preferences need to be understood.
  • For instance, calculation of randomly selected customer's beer order probability at a local bar.

Camera Brand Probability problem

  • Determining probability from a table using conditional probability.
  • Given that a camera purchase was at Amazon.com, calculate the probability it was a Canon brand.

Data Types

  • Understanding types of data and knowing the difference btwn time series data and cross-sectional data.

Statistics Definition

  • Definition of a statistic should be known.

Mean, Median, and Mode

  • Understanding mean, median, and mode, including which is most influenced by outliers, is required.

Frequency Case Study

  • Use a table to take a statistic like a percent or relative frequency
  • Find the number given the population size by remembering the relative frequency case study.

Empirical Rule

  • The empirical rule should be understood.

Dispersion Statistics

  • Knowing the most common statistics to show dispersion is necessary.

Variance

  • Understanding variance, what it shows, and its relation to standard deviation is important.

Covariance

  • Definition of covariance.

Collectively Exhaustive Event

  • How an event can be collectively exhaustive should be understood.

Union in Probability

  • Definition of a union in probability and recognize the notation.

Intersection in Probability

  • Understanding of the intersection of 2 events in probability notation.
  • The intersection of events A = {The Porch, Louie's, The Library, O'Connell's} and B = { The Library, O'Connell's, Logies, Volare} is {The Library, O'Connell's}.
  • The union of events A = {The Porch, Louie's, The Library, O'Connell's} and B = { The Library, O'Connell's, Logies, Volare} is {The Porch, Louie's, The Library, O'Connell's, Logies, Volare}.

Probability Summation

  • All probabilities must add up to 1.

Event Outcomes

  • When an event has one outcome, it is an elementary event.

Sample Space

  • Understanding of sample space should be there.
  • Determine the sample space for letter grades in a class.

Complement of A

  • Understanding of the complement of A given sample space S is required.

Correlation Coefficient

  • Correlation coefficient formula and calculation should be understood.

Standard Deviation

  • Deriving standard deviation from variance should be understood.

Exam Score Probability

  • Determining exam score probability given average and standard deviation.
  • Knowing if the average on exam 1 is an 85 with a standard deviation of 1.5, what is the probability you score less than 75.
  • What is the probability you score greater than a 90?

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Quiz Team

Related Documents

Exam 1 Review (Fall 2024) PDF

More Like This

Statistics: Normal Distribution Concepts
70 questions

Statistics: Normal Distribution Concepts

ConscientiousEvergreenForest1127 avatar
ConscientiousEvergreenForest1127
Statistics and Probability Concepts
48 questions
Normal Distribution Concepts
96 questions

Normal Distribution Concepts

TransparentMusicalSaw1414 avatar
TransparentMusicalSaw1414
Use Quizgecko on...
Browser
Browser