Data collection and conclusions1.The graph above shows the results of a controlled experiment designed by a scientist to determine the effect of magnetic field strength on the growth of sunflower plants. 500young sunflower plants were randomly assigned to the control or experimental group. In the control group, the scientist grew 250 sunflower plants under normal local geo-magnetic field conditions(30 microteslas). In the experimental group, the scientist grew 250 sunflower plants identically except under a lower geomagnetic field (20 microteslas). Based on the results of this experiment, which conclusion is NOT valid?A.Sunflower plants grown under lower magnetic field conditions were more likely to weighmore than sunflower plants grown under normal magnetic field conditions.B.There is evidence of an association between the strength of magnetic field and height insunflower plants.C.Sunflower plants grown under lower magnetic field conditions were more likely to be tallerthan sunflower plants grown under normal magnetic field conditions.D.Members of the control group were more likely to grow to less than 100 inches than membersof the experimental group.Correct answer: A Difficulty level: 22.A researcher wants to conduct a survey to gauge United States (U.S.) voters' opinions about the U.S. Congress. Which of the following should NOT be a component of this survey?A.The researcher collects data from the survey takers.B.The researcher analyzes data from the survey takers.C.The researcher distributes the survey to 10,000 randomly selected U.S. citizens aged 18 andolder.D.The researcher distributes the survey to 10,000 residents of a Washington D.C. neighborhood. Correct answer: D Difficulty level: 23.A scientist wants to collect data about the effects of gravity on the growth of soybean plants. To test her hypothesis that soybeans grow better in a zero-gravity setting, she randomly assigns the plants into one of two groups. The first group is grown in typical soybean growing conditions in a greenhouse on earth, and the second group is grown in a zero-gravity, yet otherwise identical greenhouse in a space station. Which of the following is the best description of the research design for this study?A.Controlled experimentB.Observational studyC.Sample SurveyD.None of the aboveCorrect answer: A Difficulty level: 24.A researcher representing a city government wants to measure public opinion about recycling by asking 1,000 randomly selected residents a series of questions on the subject. Which of the following is the best description of the research design for this study?A.Observational studyB.Sample SurveyC.Controlled experimentD.None of the aboveCorrect answer: B Difficulty level: 25.In order to determine whether children who have just watched cartoons will perform better on cognitive tasks than children who have not just watched cartoons, researchers randomly divided 60 preschoolers into three groups. For nine minutes, one group watched a rapid-paced cartoon, one group watched a slower-paced educational program, and one group colored. They then administered standardized tests to determine the immediate impact of the children’s previous nine minutes of activity. Which of the following is the best description of this type of research design?A.An observational study, a study in which investigators observe subjects and measure variablesof interest without assigning treatments to the subjects.B. A controlled experiment, a study in which an investigator separates subjects into a controlgroup that does not receive a treatment and an experimental group that receives a treatment, and then observes the effect of the treatment on the experimental group.C. A sample survey, a study that obtains data from a subset of a population, usually through aquestionnaire or interview, in order to estimate population attributes.D.None of the aboveCorrect answer: B Difficulty level: 26.The table above shows the results of an observational study designed to observe the social media habits of different age groups of internet users in the U.S. between 2005 and 2013. Based on the results of this study, which of the following conclusions are valid?I: In each year of the study, U.S. internet users aged 18-29 were more likely to use social media than any other age group in the study.II: Over the course of the study, there was growth in the percentage of U.S. internet users that use social media across all of the age groups observed.III: The rate of social media use by U.S. internet users will continue to rise in the future.IV: Social media was more likely to be used by a U.S. internet user aged 30-49 in 2013 than it was by a U.S. internet user aged 30-49 in 2005.A.I onlyB.I and IVC.I, II, and IVD.I, II, III, and IVCorrect answer: C Difficulty level: 37.The table above shows the results of a controlled experiment designed to determine the effect that adding sodium chloride to water has on the boiling point of water at sea level. Based on the results of this experiment, what conclusion is NOT valid when up to three tablespoons of sodium chloride are added to one quart of water?A.The more sodium chloride that is added to boiling water, the higher the water's boilingtemperature becomes.B.The more sodium chloride that is added to water, the longer the water will take to boil.C.There is an association between adding sodium chloride to water and an increase in theboiling temperature of water.D.There is a linear relationship between sodium chloride added to water and the water's boilingtemperature.Correct answer: B Difficulty level: 38.Louis Pasteur conducted a famous experiment that addressed the question: "Can microorganisms generate spontaneously?" To replicate the experiment, in the control group, purify water in closed flasks by boiling them, and then let the water sit in the closed flasks at room temperature for a predetermined period of time. In the experimental group, purify water in identical closed flasks by boiling them. However, before letting the experimental group sit at room temperature for the predetermined period of time, break the top stem of these flasks to expose the water to outside elements. After the predetermined period of time, if no microorganisms are observed in the control flasks and several thousand microorganisms are observed in each experimental flask, which of the following conclusions are valid?I: When closed off to outside elements, purified water will not spontaneously generate microorganisms.II: Exposing water to the elements causes the water to become harmful to humans.III: Breaking the top stem of the experimental flask allowed the microorganisms to enter the purified water.IV: Not breaking the stem of the control flask prevented microorganisms from entering the purified water within.A.III onlyB.III and IVC.I,III, and IVD.I,II,III, and IVCorrect answer: C Difficulty level: 39.A writer for a high school newspaper is conducting a survey to estimate the number of students that will vote for a particular candidate in an upcoming student government election. All students at the high school are eligible to vote in the election, and the writer decides to select a sample of students to take the survey. Which of the following sampling methods is most likely to produce valid results?A.Survey every fifth student to enter the school library.B.Survey every fifth student to arrive at school one morning.C.Survey every fifth senior to arrive at school one morning.D.Survey every fifth student to enter the school stadium for a football game.Correct answer: B Difficulty level: 310.The graph shown above shows the results of an observational study of corn grain yield, in bushels per acre, versus rate of nitrogen fertilizer solution, in pounds per acre, applied to crops. Based on the results of this study, which conclusion is best supported by the data?ing nitrogen in the soil causes greater grain yield.B.There is evidence of a linear association between the amount of nitrogen applied to the soiland the grain yield.C.There is evidence of an association between the amount of nitrogen applied to the soil and thegrain yield, but the association does not appear to be linear.D.Low levels of nitrogen in the soil leads to poor grain yield.Correct answer: C Difficulty level: 311.The table above shows the results of a controlled experiment designed to determine the effect of tailgate position on the fuel consumption of a pickup truck. Based on the results of this experiment, which conclusion is NOT valid?A.The truck needed the least fuel to travel a set distance when its tailgate was all the way up.B.The truck needed the most fuel to travel a set distance when its tailgate was all the way down.C.There is an association between the truck's tailgate position and the amount of fuel needed totravel a set distance.D. A truck driver who drives with the tailgate up will spend less money on fuel than when thetruck driver drives with the tailgate down.Correct answer: D Difficulty level: 412.An ecologist conducted measured the population of brown bears in a North American region and the number of deforested acres in the same region since the year 2000.The study concluded that as the population of brown bears steadily decreased, the number of deforested acres steadily increased during the same time period. Based on this data, which conclusion is valid?A.The increase in the number of deforested acres in the North American region since 20002000caused the decrease in the brown bear population there during the same time period.B.The decrease in the brown bear population in the North American region since 20002000caused the increase in the number of deforested acres there during the same time period.C.There is no evidence of an association between the brown bear population levels in the NorthAmerican region and the number of deforested acres there in the years since 20002000.D.There is evidence of an association between the brown bear population levels in the NorthAmerican region and the number of deforested acres there in the years since 20002000. Correct answer: D Difficulty level: 413.The graph to the left shows the results of a controlled experiment designed to determine how effective a new toothpaste is at preventing cavities. A researcher randomly selected 1,000 healthy adults **parable dental habits and records to participate and randomly assigned participants to either the experimental or control group. In the experimental group, 500 participants were asked to use the new toothpaste for a 6 month period. In the control group, the remaining 500 participants were asked to continue using their normal toothpaste during the same 6 month period. Based on the results of this experiment, which conclusion is NOT valid?A.There is an association between the participants brushing their teeth every day and notdeveloping new cavities.B.There is an association between using the new toothpaste and not developing new cavities.C.Four hundred members of the experimental group reported no new cavities during the study.D.Members of the control group were more likely to develop cavities than members of theexperimental group.Correct answer: A Difficulty level: 414.Adapted from "The Role of Deliberate Practice in the Acquisition of Expert Performance," by K.A. Ericsson, R. Th. Krampe, and C. Tesch-Romer, 1993, Psychological Review, 700(3).In a famous study on the role of practice in the acquisition of expert performance, **pared the amount of time spent on solitary practice, based on diaries and retrospective estimates, for four groups of violinists: professional violinists, the best expert violinists, good expert violinists, and the least accomplished expert violinists (lesser experts). Based on the results of this study, which conclusion is best supported by the data?A. A violinist who practices about 10,000hours by the age of 20will become a professionalviolinist.B.By the age of 20, the best experts and professional violinists in the study had practiced morethan twice as much as the least accomplished violinists.C.The least accomplished violinists did not practice as much because they became discouraged.D.There is no evidence of an association between increased solitary practice before the age of 18and level of expertise as a violinist.Correct answer: B Difficulty level: 415.The above table shows the percentages of the Canadian population as well as the percentage of Canadian hockey players in the National Hockey League (NHL) residing in cities of various sizes. Based on the results of this study, which conclusion is best supported by the evidence?A.There is evidence that players from mid-sized cities (100,000-499,999) are overrepresented inthe NHL.B.Players from very **munities (<1,000) do not have as many opportunities for elite training asplayers from **munities.C.Cities with populations larger than 500,000 are underrepresented in terms of players in theNHL because players in **munities face too **petition.Players in large cities have more opportunities for elite training than do players from smaller cities.Correct answer: A Difficulty level: 416.A local tv news station wants to determine how often and through which medium their viewers check the weather. Which of the following survey methods is most likely to produce valid results?A.Ask a random sample of their viewers how much they enjoy the weather portion of the localnews.B.Ask a random sample of their viewers whether they own a smartphone.C.Ask a random sample of members of the local meteorological society whether they watch thelocal news.D.Ask a random sample of their viewers how often and when they use various sources to obtainweather information.Correct answer: D Difficulty level: 317.A writer for a high school newspaper is conducting a survey to estimate the number of students that will vote for a particular candidate in an upcoming student government election. All students at the high school are eligible to vote in the election, and the writer decides to select a sample ofstudents to take the survey. Which of the following sampling methods is most likely to produce valid results?A.Survey every fifth student to enter the school library.B.Survey every fifth student to arrive at school one morning.C.Survey every fifth senior to arrive at school one morning.D.Survey every fifth student to enter the school stadium for a football game.Correct answer: BN Difficulty level: 3。