Exam 1: Introduction to Data

Data can be defined as numbers in context. Suppose you are given the following set of numbers: What additional information would allow you to define these numbers as data?

Researchers conducted an experiment to determine if children who participate in a new after-school tutoring program do better on state-mandated tests than children who do not attend the program. What are the treatment and outcome variables?

Researchers conducted a study and determined that students who carpool have less friends than students who ride the bus to school. Can we conclude that carpooling causes students to have less friends?

Determine if the following scenario is an observational study or a controlled experiment and explain your reasoning. A school teacher is interested in determining whether students who take multiple choice tests do better than students who take true/false tests. She has been giving multiple choice tests since she started teaching and is wondering if she should change her testing method. She randomly assigns half of her students to take a multiple choice test about grammar rules, and the other half to take a true/false test about grammar rules. She compares the test scores of the students in each group.

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 reviews her patients' medical records and finds that a higher proportion of people who take the medication have fewer migraines than those who did not take the medication.

Data can be defined as numbers in context. Suppose you are given the following set of numbers: What additional information would allow you to define these numbers as data?

According to the following data table, which variable(s) is(are) categorical?

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. -Can we conclude that the reduction of migraines was caused by the new medication? Explain your reasoning.

In a study of 1200 adults, 480 out of the 630 women in the study said they attended a state college or university. What percent of women attended a state college or university?

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

In a study of 1350 elementary school children, 118 out of the 615 girls in the study said they want to be a teacher when they grow up. What percent of girls want to be a teacher when they grow up?

According to the following two-way table, what percent of people in the sample take naps?

In a recent survey at UCLA, some incoming freshmen students were asked if they planned to take more than one math class before they graduated. What is the population of interest here and what is the sample?

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. -Was the new medication effective for cancer remission?

Researchers conducted a study and determined that students who participate in sports are happier than students who do not. Can we conclude that participating in sports makes students happier?

In a recent study of 1200 adult smokers, 125 out of the 560 males in the study said they were interested in joining a help group to quit smoking. What percent of males are interested in joining this group?

According to the following two-way table, what percent of people in the sample eat breakfast?

What types of variables are represented in a two-way table? Give an example.

Give an example of how data could be collected about you on a daily basis.

A gym is offering a new 6-week diet plan for its members. Members who sign up for the program are weighed and measured once a week for the duration of the program. The owners of the gym want to know if the diet plan actually helps people lose weight. What variable could be a possible confounding factor in determining the cause of weight loss?