Statistics Correlation and Regression Examples
33 Questions
0 Views

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to lesson

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What is the total value of $x^2$ from the provided table?

  • 363
  • 320
  • 440 (correct)
  • 400
  • Which year had the highest production in the sugar factory's data?

  • 1973
  • 1971
  • 1974 (correct)
  • 1970
  • How many years are represented in the production data for the sugar factory?

  • 7 (correct)
  • 8
  • 6
  • 5
  • From the table, which $xy$ value corresponds to the $x$ value of 9?

    <p>63</p> Signup and view all the answers

    What is Karl Pearson's coefficient of correlation likely to measure in this data context?

    <p>The correlation between two sets of variables</p> Signup and view all the answers

    What is the correct value of $xy$ for the first entry in the table?

    <p>3808</p> Signup and view all the answers

    How many students' marks are provided in the example for OS and DS?

    <p>9</p> Signup and view all the answers

    What is represented by $x^2$ in the table?

    <p>The square of the X values</p> Signup and view all the answers

    In the context of Karl Pearson’s coefficient of correlation, what is the primary implication of a coefficient close to 1?

    <p>A perfect positive correlation between the variables</p> Signup and view all the answers

    What is the significance of calculating the ranks in two subjects for the marks obtained?

    <p>To analyze the relative performance of students in OS and DS</p> Signup and view all the answers

    What is the formula used to determine the number of ways to choose 2 socks from 4 socks?

    <p>$4C2$</p> Signup and view all the answers

    What event represents drawing two defective chips from a total of 15, where exactly two are defective?

    <p>$5C2 * 10C1$</p> Signup and view all the answers

    How many total ways are there to select 3 chips from a box of 15?

    <p>$15C3$</p> Signup and view all the answers

    In the context of the horse race, what type of probability is being assessed when determining the chance of picking the winning horse?

    <p>Simple probability</p> Signup and view all the answers

    If 5 horses are in a race and a person picks 2 at random, what calculation would best represent the probability of selecting the winning horse?

    <p>$1/5$</p> Signup and view all the answers

    What is the value of $a_0$ in the derived quadratic regression equation?

    <p>0.571429</p> Signup and view all the answers

    Which variable represents the coefficient for the $x^2$ term in the quadratic equation?

    <p>a_2</p> Signup and view all the answers

    What is the equation of the quadratic regression derived from the provided data?

    <p>y = 0.571429 + x + 1.107142 x^2</p> Signup and view all the answers

    How many data points (N) were used in the quadratic regression example?

    <p>7</p> Signup and view all the answers

    Which value represents the number of equations formed for the quadratic regression?

    <p>3</p> Signup and view all the answers

    What does the variable 'd' represent in the Spearman's rank correlation table?

    <p>The difference between ranks</p> Signup and view all the answers

    In Spearman's rank correlation, what is the purpose of calculating $d^2$?

    <p>To minimize the differences</p> Signup and view all the answers

    What is the relationship between the values in columns 'x' and 'y' as presented?

    <p>They conform to a quadratic pattern</p> Signup and view all the answers

    Which of the following represents the maximum value of $y$ in the given data?

    <p>14</p> Signup and view all the answers

    In the Spearman's rank calculation, what is 'n' when applying the formula?

    <p>10</p> Signup and view all the answers

    What principle is used to determine the constant 'a' in the p.d.f. of a continuous random variable?

    <p>The sum of probabilities must equal 1.</p> Signup and view all the answers

    When computing P(X < 1.5) for a continuous random variable, which of the following is essential?

    <p>The total area under the p.d.f. curve up to 1.5.</p> Signup and view all the answers

    What scenario corresponds to finding P(1.5 < X < 2.5) for a random variable?

    <p>The area under the p.d.f. curve between 1.5 and 2.5.</p> Signup and view all the answers

    What is the probability of getting no fives when a die is rolled three times?

    <p>0.421875</p> Signup and view all the answers

    If one five occurs in three rolls of a die, what is the corresponding probability?

    <p>0.417</p> Signup and view all the answers

    What is the probability of getting three fives when rolling a die three times?

    <p>0.027</p> Signup and view all the answers

    In a probability density function (p.d.f.), which statement is true regarding the total area under the curve?

    <p>It must equal one.</p> Signup and view all the answers

    How is the probability of an event computed using cumulative distribution function (CDF)?

    <p>It's the difference between probabilities at two points.</p> Signup and view all the answers

    Study Notes

    Example 2.3

    • The example demonstrates calculating Karl Pearson's coefficient of correlation using a table of production data for a sugar factory over several years.
    • The table lists year, production, and calculated values for x2, y2, and xy for each year.
    • The formula for calculating the correlation coefficient is provided, but the actual calculations are not shown.

    Example 2.7

    • The example demonstrates calculating Spearman's rank correlation coefficient using a table of marks obtained by 9 students in two subjects: OS and DS.
    • The table lists the marks in each subject, the rank for each student in each subject, the difference between the ranks (d), and the square of the difference (d2).
    • The formula for calculating the Spearman's rank correlation coefficient is provided, but the actual calculations are not shown.

    Example 2.13

    • The example demonstrates computing a quadratic regression equation using a table of data points with corresponding x and y values.
    • The table includes x, y, x2, x3, x4, xy, and x2y for each data point.
    • Three equations are derived to solve for the coefficients a0, a1, and a2 in the quadratic regression equation.
    • The simultaneous equations for a0 and a2 are solved, and the solution for a1 is derived from a separate equation.
    • The final quadratic regression equation is presented in the form y = a2x2 + a1x + a0.

    Example 3.4

    • The example demonstrates calculating the probability of drawing exactly two defective chips from a box containing 15 chips, 5 of which are defective.
    • The sample space (S) is defined as drawing 3 chips randomly from the box.
    • The event A is defined as drawing 3 chips where exactly 2 are defective.
    • The probability of event A is calculated using the formula: P(A) = (n(A)) / (n(S)).

    Example 3.5

    • The example involves a horse race with 5 horses and a person (X) who bets on two horses chosen randomly.
    • The example does not include the calculations for determining the probabilities.

    Example 4.15

    • The example describes a continuous random variable X with a probability density function (p.d.f.).
    • The p.d.f. is defined by the function: f(x) = ax, for 0 ≤ x ≤ 2.
    • The problem asks for determining the constant 'a', computing P(X < 1.5), and finding P(1.5 < X < 2.5).

    Example 5.1

    • The example asks for the probability of the following events when rolling a die three times:
      • No fives turning up
      • One five turning up
      • Three fives turning up
    • The example does not include the calculations for determining the probabilities.

    Studying That Suits You

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

    Quiz Team

    Description

    This quiz explores examples of calculating correlation coefficients, including Karl Pearson's and Spearman's rank correlation, alongside quadratic regression equations. Each example is accompanied by data tables for better understanding. Test your knowledge of these statistical concepts by reviewing key formulas and calculations.

    More Like This

    Use Quizgecko on...
    Browser
    Browser