Exam 1: Introduction to Data

In a study of 900 adults, 45 out of the 325 men in the study said that they preferred to rent a movie on DVD rather than going out to a movie theater. -What is the approximate percentage of women who participated in this study?

In a study of 1050 adults, 175 out of the 650 women in the study said that they preferred to drive a SUV to driving a compact car. -What is the approximate percentage of study participants who are women in this study who said that they prefer to drive a SUV to driving a compact car?

Answer the question using the following table showing fatal injury counts by four major categories from 2004-2009 for Michigan Residents. The table shows total counts for all ages and both sexes. Fatal injuries Unintentional Injuries 3,244 3,353 3,496 3,655 3,624 3,589 Self-inflicted/Suicide 1,096 1,103 1,132 1,123 1,173 1,164 Assault/Homicide 672 673 720 702 642 658 All other fatal injuries 466 404 414 446 446 506 All fatal Injuries 5,478 5,533 5,762 5,926 5,885 5,917 -What is the rate of fatal injuries caused by Assault/Homicide in 2008?

In a study of 1050 adults, 175 out of the 650 women in the study said that they preferred to drive a SUV to driving a compact car. -What is the approximate percentage of study participants who are women?

The two-way table below shows teenage driver gender and whether or not the respondent had texted at least once while driving during the last thirty days. Teenage driver- Male Teenage driver- Female Texted at least once while driving during past 30 days. 5 7 Had not texted at least once while driving during the past 30 days. 11 9 -What percentage of the sample had texted at least once while driving in the past thirty days?

Explain the difference between an observational study and an anecdote. Be sure to provide an example of each.

The two-way table below shows the survey results when sixty adults were asked whether they had made a clothing purchase in the last thirty days. Male Female Purchased clothing in the last thirty days. 10 29 Had not purchased clothing in the last thirty days. 10 11 -Of the adult males surveyed, what percentage had made a clothing purchase in the last thirty days?

Consider the following statement, "Babies who breastfeed are less likely to grow into children with behavioral problems by the time they reach age 5 than those who receive formula milk." Which of the following is a plausible confounding variable in this study?

The following is reported in a local newspaper: "The majority of Michigan voters want to keep the individual pricing law. A poll of 600 voters showed 51% wanting to keep the law and 39% supporting its repeal." -If possible, answer the following questions about the context of this study: a. What are the objects of interest? b. What variables are being measured? c. How were the variables measured? d. Who collected the data? e. How did they collect the data?

A state senator's comments about the dangers of global warming are an example of what type of variable?

Indicate whether the study described is an observational study or a controlled experiment. -Researches want to find out which U. S. movie has the most positive audience reaction for the current week. As they exited a randomly selected movie theater, movie-goers were asked to give the movie they had just viewed a letter grade of A, B, C, D, or F. In this scenario, the movie-goers Are an example of a_{--------------------} .

A two-way table is useful for summarizing and comparing what?

Indicate whether the study described is an observational study or a controlled experiment. -The gender of a sample of adults was recorded, and then they were asked whether they had used a postage stamp in the last thirty days. A good way to organize this categorical data is in a

The following is reported in a local newspaper: "The majority of Michigan voters want to keep the individual pricing law. A poll of 600 voters showed 51% wanting to keep the law and 39% supporting its repeal." -Identify the sample and the population it is most likely intended to represent.

Explain what a numerical variable is and give an example of a numerical variable.

Suppose you are presented with a dataset containing the ages of 50 randomly selected adults and the amount of money they spent at a certain grocery store on a certain day. Which of following questions do not need to be asked about the dataset?

The average number of hours spent completing statistics homework for a randomly selected group of statistics students is an example of what type of variable?

Answer the question using the following table showing fatal injury counts by four major categories from 2004-2009 for Michigan Residents. The table shows total counts for all ages and both sexes. Fatal injuries Unintentional Injuries 3,244 3,353 3,496 3,655 3,624 3,589 Self-inflicted/Suicide 1,096 1,103 1,132 1,123 1,173 1,164 Assault/Homicide 672 673 720 702 642 658 All other fatal injuries 466 404 414 446 446 506 All fatal Injuries 5,478 5,533 5,762 5,926 5,885 5,917 -Explain what a categorical variable is and give an example of a categorical variable.

A sample of 984 voters was asked in a survey, "Do you support your state's helmet law for motorcycles? " The results are summarized in a two-way table: Male Female Support the helmet law 214 380 Oppose the helmet law 185 205 -Overall, what percentage of the sample supports the helmet law? Round to the nearest whole percent.

A sample of 984 voters was asked in a survey, "Do you support your state's helmet law for motorcycles? " The results are summarized in a two-way table: Male Female Support the helmet law 214 380 Oppose the helmet law 185 205 -Among the women surveyed, what percent support the helmet law? Round to the nearest whole percent.