Exam 1: Introduction to Data

Determine if the following scenario is an observational study or a controlled experiment and explain your reasoning. A doctor is interested in determining whether a certain medication is effective at treating abdominal pain. He reviews his patients' medical records and finds that a higher proportion of people who took the medication fewer abdominal pain symptoms than those who did not take the medication.

Determine which of the following five variables are numerical and which are categorical. age, gender, weight, ethnicity, favorite math class

According to the following two-way table, why are percentages more useful than counts to compare the amount of males and females who take naps?

In the following table, gender is a categorical variable. Give one possible way the variable could have been coded.

According to the following two-way table, why are percentages more useful than counts to compare pet preferences between males and females?

Use the following information for following questions: A group of 500 patients who suffer from skin cancer were asked to participate in a study to determine the effectiveness of a new medication. The patients were randomly divided into two groups, one that was given the actual medication, and one that received a placebo pill. A good outcome was defined as the cancer being in remission after 6 months of treatment. The results of the study are below. -Approximately what percent of patients who took the medication had cancer remission?

Determine which of the following five variables are numerical and which are categorical. age, gender, height, favorite candy, eye color

A college is offering a new free tutoring program for students in an introductory statistics class. The school wants to know if this new program improves students' test scores on their midterms and final exams. What variable could be a possible confounding factor in determining why students' scores improved or not?

Use the following information for following questions: A group of 500 patients who suffer from hypothyroidism, a condition in which your thyroid does not produce enough of certain hormones, were asked to participate in a study to determine the effectiveness of a new medication. The patients were randomly divided into two groups, one that was given the actual medication, and one that received a placebo pill. The results of the study are below. -Was the new medication effective in treating hypothyroidism?

In a recent school poll, the administrators asked if students were satisfied with the school's course offerings. What is the population of interest here?

Researchers conducted an experiment to determine if having a dog day on college campuses during final exam week lowers students' stress levels. A dog day is when dogs from a local animal shelter are brought onto campus for students to play and interact with. What are the treatment and outcome variables for this experiment?

Give an example of one categorical variable and one numerical variable.

Researchers conducted a study and determined that coworkers who socialize outside of work are more productive than coworkers who do not. Can we conclude that socializing outside of work causes coworkers to be more productive? Explain your reasoning.

Determine if the following scenario is an observational study or a controlled experiment. A doctor is interested in determining whether a certain medication reduces migraines. She randomly selects 100 people for his study - 50 who will take the medication, and 50 who will take a placebo. The patients are examined once a week for six weeks.

Give an example of how anecdotal evidence can be used to persuade consumers to purchase a product.

The following data table is organized using which method?

Use the following information for following questions: A group of 500 patients who suffer from skin cancer were asked to participate in a study to determine the effectiveness of a new medication. The patients were randomly divided into two groups, one that was given the actual medication, and one that received a placebo pill. A good outcome was defined as the cancer being in remission after 6 months of treatment. The results of the study are below. -Can we conclude that the cancer remissions were caused by the new medication?

What does it mean for an experiment to be double-blinded?

Use the following information for following questions: A group of 500 patients who suffer from severe migraines were asked to participate in a study to determine the effectiveness of a new medication. The patients were randomly divided into two groups, one that was given the actual medication, and one that received a placebo pill. A good outcome was defined as a reduction in the number of migraines during a month's time. The results of the study are below. -Approximately what percent of patients who took the medication had a reduction in the amount of migraines?

In Los Angeles, juice cleansing is very popular. Some people have claimed that the cleanses are beneficial for weight loss, body detoxification, and treatment and prevention of illnesses. Can we conclude that juice cleansing causes these health benefits?