My Rough Work #1

Author

Kailyn McFadden

Question 1

Attend your workshops each week and submit the workshop mini-assignments Ensure that you include all of the information in your Discord questions when asking about an R Assignment, WeBWorK question, or Mini-Exercise Attend office hours if you have questions Email your instructor if something personal is affecting your ability to succeed in the course; they are a real person and are here to help you Use threads when responding to Discord questions Use Discord to ask content questions and to interact with the teaching team for non-personal and non-private questions Keep up with the WeBWorK questions each week Attend lectures or watch the lecture recordings if you were unable to attend Take care of yourself: try to eat some form of balanced diet, get outside, go for a walk if you are able, and get some kind of movement or exercise Read the FREE textbook sections

Question 2

  1. 3 + 6
  2. 3^4
  3. 2+3-4*5
  4. 12/47

Question 3

1 / 100000000 [1] 1e-08 1E-08

Question 4

  1. Venus os the closest planet to the sun - False
  2. You’re so vain. You probably think this song is about you. - True
  3. You are going to give this class a chance and not judge it immediately for being a ‘MATH’ course, right? - True
  4. The Earth is flat - False
  5. It’s me, hi, I’m the problem it’s me. - false

Question 5

  1. Favourite colour: Categorical, nominal
  2. Number of countries visited: Numerical, discrete
  3. Number of times flying in an airplane: Numerical, discrete
  4. Satisfaction level with job (Very Dissatisfied, Dissatisfied, Neutral, Satisfied, Very Satisfied): Categorical, ordinal
  5. Level of education (High School, Bacheler’s, Master’s, PhD): Categorical, ordinal
  6. Type of car owned (Sedan, SUV, Truck, Van): Categorical, nominal

Question 6

  1. Data obtained from a categorical scale: can be numbers or other symbols

  2. Data which is gathered from a subset of the population is known as a: sample

  3. All the data collected in a particular study are referred to as the: data set

Question 7

Which of the following is NOT a principle of experimental design? D. Maximization

Which of the following best describes the role of observational studies in research? D. Observational studies often provide the basis for hypotheses that are later tested in experiments

Which of the following is an example of a confounding variable in a study examining the relationship between ice cream sales and the number of drownings at a beach? A. Temperature

What are the benefits of a simple random sampling? Equal chance of inclusion for each member It is simple Guarantees inclusion of rare characteristics Allows the researcher to determine causality Confounding variables are dealt with implicitly Which of the following are associated with bias? Non-random sampling Self-selection ““Blocking”” incorrect (first attempt) Interviewer bias Non-response

Experiments, performed correctly, allow us to determine causal relationships: True

Observational studies are completely useless since no causal inference can be made based on their findings: False

Question 8

In observational studies, the researcher manipulates one of the variables being studied. False

  1. In simple random sampling, the selection of one unit does not depend on the selection of any other unit. True

  2. An advantage of a placebo control group in an experiment is that it helps to isolate the effects of the treatment from other factors. True

Question 9

  1. Census - An attempt to include every member of the population in a study (A)
  2. Non-response bias - A significant portion of selected participants do not respond (C)
  3. Population - The entire group of interest (D)
  4. Experiment - Researchers assign treatments to cases (E)
  5. Parameter - A numerical summary calculated on the entire population (B)

Question 10

  1. In a randomized experiment, the target population refers to the group of individuals who will all be part of the study. - True (1st), False (correct)

  2. In an experiment, the population size is often larger than the sample size to ensure generalizability of the results. - False

  3. MATH 1051 has 700 students in total. Kat and Wes want to know what these students’ favourite food is and so randomly sample 50 students from section S and 15 students from section R. The population size is 700. - False (1st), True (correct)

Question 11

  1. A school district is testing the effectiveness of a new teaching method for improving math skills in elementary school students. They select two classrooms with similar demographics. In Classroom X, the traditional teaching method is used, while in Classroom Y, the new teaching method is implemented. Students are randomly assigned to classrooms. At the end of the semester, both groups of students take the same math test, and the school district compares the average scores to evaluate the impact of the new teaching method.
  • Randomized Experiment
  1. A researcher is interested in the effect of sleep on memory retention. They recruit 30 college students and randomly assign them to two groups. Group X is allowed to sleep for 8 hours before taking a memory test, while Group Y is only allowed 4 hours of sleep. Both groups then take the same memory test, and the researcher compares their performance to determine if sleep duration has an impact on memory retention.
  • Randomized Experiment
  1. A transportation analyst is interested in studying traffic congestion at an intersection. They set up a camera to record traffic flow throughout the day. The analyst later reviews the footage to analyze traffic patterns, identify peak congestion times, and potentially suggest improvements for traffic management.
  • Observational Study

Question 12

  1. Observational studies involve collecting data without interfering with how the data arise. - True
  2. Observational studies allow researchers to infer causality. - False
  3. The reason for randomizing in an experiment is to try to make each group, on average, the same except for the variables under consideration. -True
  4. Randomized experiments allow researchers to infer causality. - True
  5. All experiments (randomized or not) involve manipulating variables to observe their effects on some outcome(s). - True
  6. Observational studies take place in the real world, more often than not. - True

Question 13

In a study of 550 college students, 150 reported regularly skipping breakfast. What proportion of students in this sample skip breakfast? Answer: Math Input: 0.273 In a randomized experiment, 220 participants are to be equally divided between treatment and control groups. How many participants should be in each group? Answer: Math Input: 110 In a study of 200 adults, 80 reported exercising regularly. What percentage of the sample exercises regularly? Answer: Math Input: 40 A researcher conducts a survey where 300 people are contacted and 165 respond. What is the response rate for this survey? Answer: Math Input: 0.55 In a study on the effect of a new teaching method, students are divided into two groups: 30 in the treatment group and 30 in the control group. If 27 students in the treatment group show improvement compared to 21 in the control group, what is the difference in the proportion of students showing improvement between the two groups? Answer: Math Input: 0.20

Question 14

  1. Select all of the categorical variables: Zip code Hair color Blood type

  2. Select all of the continuous numerical variables: pH level of a solution Time to complete a marathon Height in meters

  3. Which of the following is an example of an ordinal categorical variable? Education level

  4. Select all of the discrete numerical variables: Count of cars in the parking lot Year of birth Number of students in MATH 1051

Question 15