Chapter 1 EOC Problems
In each of the following situations, data are obtained by conducting a research study. Classify each research study as experimental or correlational.
A statistics student interested in gender and grooming collects data on the shower length and gender of arch person taking a shower from a random sample of showers. - CORRELATIONAL An economist is interested in the demand behavior of rats. Rats in a rat lab have two levers in their cages. Pressing one lever dispenses Tom Collins mix (without alcohol); pressing the other lever dispenses the same amount of a sodium saccharin solution. Psychologists obtain data on the demand behavior by altering the total number of presses required to dispense each of the fluids. - EXPERIMENTAL A professor of ophthalmology is interested in developmental precursors of vision disorders. He collects data from the sample of teenagers on right eye vision, left eye vision, and whether the bedroom light was kept off or on as they slept during the night as babies. - CORRELATIONAL
You wants to find out whether caffeine mitigates the effect of alcohol on reaction time. To study this, you administer to your subjects a drink that is equivalent to three 12-ounce beers, followed by the equivalent of two cups of coffee. Then your subjects complete a simulated driving task in which they must follow a fixed speed limit while driving on a straight road. Wind periodically and randomly pushes the simulated vehicle left, right, or not at all. Speed is measured in miles per hour above or below 60-mph speed limit, with 1 mph being the smallest unit on the scale. Suppose the first subject scores 5 mph. Determine the real limits of 5. when measuring weight on a scale that is accurate to the nearest 0.1 kilogram, what are the real limits for the weight of 104 kilograms? when measuring weight on a scale that is accurate to the nearest 0.2 kilogram, what are the real limits for the weight of 52 kilograms?
Lower Real Limit: 4.5 Upper Real Limit: 5.5 103.95 - 104.05 51.9 - 52.1
In a study published in the American Psychological Associations Journal of Personality and Social Psychology, 227 college students were asked to rate their level of aggression and indicate their level of exposure to video game violence. The study found that student who reported playing more violent video games engaged in more aggressive behavior. Which of the following conclusions can you make on the basis of this study? Violent video games make students more aggressive Playing violent video games is associated with more aggressive behavior Nonviolent video games make students less aggressive There is no relationship between violent video games and aggression
Playing violent video games is associated with more aggressive behavior
Suppose a researcher compiled a data set consisting of the following variables for a sample of 100 homeowners. For each variable, select whether it is discrete or continuous. The number of meals eaten out in the last week The number of television sets in the household Shoe size Body temperature Miles driven in the last year
The number of meals eaten out in the last week - Discrete The number of television sets in the household - Discrete Shoe size - Discrete Body temperature - Continuous Miles driven in the last year - Continuous Height in inches - Continuous Pant size - Discrete Number of countries visited - Discrete Number of pets in the household - Discrete Pounds of chocolate consumed in the past year - Continuous Number of football games ever attended - Discrete Number of sons or daughters - Discrete Highest grade completed - Discrete Weight in pounds - Continuous Age - Continuous
A researcher in a medical school would like to test the effectiveness of different insomnia treatments. She conducts a study on 120 volunteers, who are randomly assigned to five different insomnia treatment groups, one of which is a control group receiving a placebo. The number of hours slept per night is recorded for each participant over two weeks. Researchers at a medical school conducted a study to test the effectiveness of a new drug for lowering cholesterol. The 52 subjects who volunteered for the study were each given a randomly generated number. Subjects with an odd number were given the new drug, while those with an even number were given a placebo. Cholesterol levels before and after the treatment were measured for each subject, and the differences were computed.
This study is an example of AN EXPERIMENTAL study The number of hours slept per night over two weeks is the DEPENDENT variable. The type of insomnia treatment is the INDEPENDENT variable. This study is an example of AN EXPERIMENTAL study The difference in cholesterol level is the DEPENDENT variable. The treatment with drug or placebo is the INDEPENDENT variable.
Select the measurement scale in the right column that best matches the description in the left column. Note that each scale (nominal scale, ordinal scale, interval scale, and ratio scale) will be used exactly once. Values measured on this scale can be compared such that you can say, for examle, one value twice as big as another value. The values of data measured on this scale can be rank ordered. The values of data measured on this scale cannot be rank ordered. The values of data measured on this scale can be rank ordered and have meaningful differences between scale points.
Values measured on this scale can be compared such that you can say, for example, one value twice as big as another value. - Ratio Scale The values of data measured on this scale can be rank ordered. - Ordinal Scale The values of data measured on this scale cannot be rank ordered. - Nominal Scale The values of data measured on this scale can be rank ordered and have meaningful differences between scale points. - Interval Scale
A psychology professor wants to know whether verbal ability is related to memory quality in current first year students at her small college. Participants in the study (first-year students at her college) complete an online memory task. The students are first shown a list of 60 words. Next they are shown a list that includes 5 new words that are conceptually similar to words on the original list. Then they are asked to identify the words on the second list that appeared on the original list. She uses the percentage of new but conceptually similar words that were mistakenly thought to be on the original list as her measure of memory quality. She also asks the students to report several characteristics such as their age, gender, and verbal SAT score. Each of the 750 first year students (338 males and 412 females) at her school volunteered to participate. The professor chose 75 students at random to complete the memory task and answer the questions. The average percentage of new but conceptually similar words that were mistakenly thought to be on the original list was 34%. The professor infers that if all 750 first year students had completed the study, the results would show that an average of 34% (plus or minus sampling error) of new words were mistakenly identified as original words because they were conceptually similar. which of the following are variables in the study? Check all that apply The students verbal SAT scores The 750 students The 75 students The students percentage of new but conceptually similar words that were mistakenly thought to be on the original list What is the population in the study? The 75 students who participated in the study The 750 first year students at the college The 34% of new words mistakenly identified as original words because they were conceptually similar What is the sample in the study? The 75 students who participated in the study The 750 student volunteers The 34% of new words mistakenly identified as original words because they were conceptually similar What is an example of a statistic in the study? 34% the average percentage of the conceptually similar words expected to be mistaken as being on the original list by the 750 students 412 females and 338 males 34%, the average percentage of conceptually similar words mistakenly thought to be on the original list by the 75 students What is an example of a parameter in the study? 34% of new but conceptually similar words that were mistakenly thought to be on the original list by the 75 first year students 75 students The actual average percentage of conceptually similar words that would be mistakenly recognized as being from the original list by the 750 first year students
Variables: The students verbal SAT scores The 750 Students The students percentage of new but conceptually similar words that were mistakenly thought to be on the original list Population: The 750 first year students at the college Sample: The 75 students who participated in the study Statistic: 34%, the average percentage of conceptually similar words mistakenly thought to be on the original list by the 75 students Parameter: The actual average percentage of conceptually similar words that would be mistakenly recognized as bing from the original list by the 750 first year students Descriptive statistics: She reports that the average percentage off new but conceptually similar words that were mistakenly thought to be on the original list was 34% Inferential statistics: She infers that if all 750 students had done the experiment, the results would show that an average of 34% (plus of minus sampling error) of new words were mistakenly identified as original words because they were conceptually similar
Are elderly women living together at home healthier than those living in a rushing home? This question was studied by a group of psychologists at the University of Delhi. For a sample of elderly women, data were collected on he following variables: Heart rate Age group (1= 60-70, 2= 71-80, 3= 81+) Body weight Environment (0=Nursing home, 1= living with family) Height Recognizing the measurement scale of the data collected on each variable is important because the type of data dictates he appropriate data summary methods and statistical procedures. Which variable(s) in the data set are measured using a nominal scale? Environment & Age group Age Group None Environment Which variable(s) in the data set are measured using the ordinal scale? Age group Age group & Heart rate Environment Environment & Age group Which variable(s) in the data set are measured using a ratio scale? Heart rate, body weight, and height Heart Rate & Age group Age group & Heart Rate Heart Rate, Age Group, & Body weight
Which variable(s) in the data set are measured using a nominal scale? Environment Which variable(s) in the data set are measured using the ordinal scale? Age group Which variable(s) in the data set are measured using a ratio scale? Heart rate, body weight, and height