Researchers from the Educational Testing Service (ETS) found that providing immediate feedback to students answering openended questions can dramatically improve students' future performance on exams ( Educational and Psychological Measurement, Feb. 2010). The ETS researchers used questions from the Graduate Record Examination (GRE) in the experiment. After obtaining feedback, students could revise their answers. Consider one of these questions. Initially, 50% of the students answered the question correctly. After providing immediate feedback to students who answered incorrectly, 70% answered correctly. Consider a bank of 100 open-ended questions similar to those on the GRE. (a) In a random sample of 20 students, what is the probability that more than 10 initially answer the question correctly?

Researchers from the Educational Testing Service (ETS) found that providing immediate feedback to students answering openended questions can dramatically improve students' future performance on exams ( Educational and Psychological Measurement, Feb. 2010). The ETS researchers used questions from the Graduate Record Examination (GRE) in the experiment. After obtaining feedback, students could revise their answers. Consider one of these questions. Initially, 50% of the students answered the question correctly. After providing immediate feedback to students who answered incorrectly, 70% answered correctly. Consider a bank of 100 open-ended questions similar to those on the GRE. (a) In a random sample of 20 students, what is the probability that more than 10 initially answer the question correctly?

Holt Mcdougal Larson Pre-algebra: Student Edition 2012

1st Edition

ISBN:9780547587776

Author:HOLT MCDOUGAL

Publisher:HOLT MCDOUGAL

Chapter11: Data Analysis And Probability

Section: Chapter Questions

Problem 8CR

See similar textbooks

Similar questions

What is an experiment?
What is meant by the sample space of an experiment?
A study of the effects of color on reducing anxiety compared anxiety test scores of participants who completed the test printed on either soft yellow paper or on harsh green paper. The scores for five participants who completed the test printed on the yellow paper were 17, 19, 28, 21, and 18. The scores for four participants who completed the test on the green paper were 20, 26, 17, and 24. Using the .05 level, one-tailed (predicting lower anxiety scores for the yellow paper), what should the researcher conclude?
A low-level CDC bureaucrat wants to please his boss by gathering evidence thatthe current government-mandated shutdown of society is not causing people’s mentalhealth to deteriorate, so that it can safely be continued for several years if anyexpert says it’s necessary.He polls a random sample of 1600 citizens, gathering data on such items asincome loss, weight gain, access to toilet paper, hours spent binge-watchingNetflix, and number of injuries caused by household fights, and compiles all thisinto a scientifically-weighted “misery index”.The mean misery index from the sample is 99.2; it seems reasonable to use apopulation standard deviation σ = 19.1.a) Does this information provide significant evidence (at the 5% level) that thenationwide mean misery index is less than 100? Set up appropriate null andalternative hypotheses, calculate the appropriate test statistic, find the P-value,and state your conclusion. (10)b) A CDC press release publishing the results of this study claims that…
A low-level CDC bureaucrat wants to please his boss by gathering evidence thatthe current government-mandated shutdown of society is not causing people’s mentalhealth to deteriorate, so that it can safely be continued for several years if anyexpert says it’s necessary.He polls a random sample of 1600 citizens, gathering data on such items asincome loss, weight gain, access to toilet paper, hours spent binge-watchingNetflix, and number of injuries caused by household fights, and compiles all thisinto a scientifically-weighted “misery index”.The mean misery index from the sample is 99.2; it seems reasonable to use apopulation standard deviation σ = 19.1.a) Does this information provide significant evidence (at the 5% level) that thenationwide mean misery index is less than 100? Set up appropriate null andalternative hypotheses, calculate the appropriate test statistic, find the P-value,and state your conclusion. b) A CDC press release publishing the results of this study claims that…
Does posting calorie content for menu items affectpeople’s choices in fast-food restaurants? According to results obtained by Elbel, Gyamfi, and Kersh(2011), the answer is no. The researchers monitoredthe calorie content of food purchases for children andadolescents in four large fast-food chains before andafter mandatory labeling began in New York City. Although most of the adolescents reported noticing thecalorie labels, apparently the labels had no effect ontheir choices. Data similar to the results obtained showan average of M = 786 calories per meal with s =85 for n =100 children and adolescents before thelabeling, compared to an average of M = 772 calorieswith s = 91 for a similar sample of n = 100 after themandatory posting.a. Use a two-tailed test with a = .05 to determinewhether the mean number of calories after theposting is significantly different than before caloriecontent was posted.b. Calculate r2to measure effect size for the mean difference.
In a study to determine if using low-intensity laser therapy reduces pain for orthodontic patients who are fitted with new braces, patients were randomly assigned to either a control group (who did not receive laser treatment) or an experimental group who did receive laser treatment.† The researchers found that the mean pain rating was lower for those in the laser treatment group than for those in the control group both two days and six days after receiving braces. The researchers used these data to determine if there was evidence to support the claim that the mean pain rating is lower for patients who receive the laser treatment. Answer the four key questions. Q, Question Type: Estimation or hypothesis testing? estimationhypothesis testing S, Study Type: Sample data or experiment data? sample dataexperiment data T, Type of Data: One variable or two? Categorical or numerical? one categorical variableone numerical variable two categorical variablestwo numerical variables…
Based on the correlation coefficient between scores on U of W Pain Inventory and the Marlowe-Crowne Reaction Inventory, is the obtained correlation coefficient consistent with the possibility that people with high levels of social desirability tend to say they would not react strongly when presented with a painful stimulus? Hint: Should the correlation coefficient between the Marlowe-Crowne Reaction Inventory and the U of W Pain Inventory be positive or negative if the “tough is socially desirable” hypothesis is true? In answering this question, you may assume that correlations that are less than +/- 0.2 are equivalent to zero.
As part of a long-term study of individuals 65 years of age or older, sociologists and physicians at the Wentworth Medical Center in upstate New York investigated the relationship between geographic location and depression. A sample of 60 individuals, all in reasonably good health, was selected; 20 individuals were residents of Florida, 20 were residents of New York, and 20 were residents of North Carolina. Each of the individuals sampled was given a standardized test to measure depression. Higher test scores indicate higher levels of depression. A second part of the study considered the relationship between geographic location and depression for individuals 65 years of age or older who had a chronic health condition such as arthritis, hypertension, and/or heart ailment. A sample of 60 individuals with such conditions was identified. Again, 20 were residents of Florida, 20 were residents of New York, and 20 were residents of North Carolina. Prepare a managerial report that summarizes…
a study of the effects of color on easing anxiety cpmpared anxiety test scores of prticipants who completed the test printed on either soft yellow paper or on harsh green paper.the scores for the five participants who cpmpleted the test on the green paper were 20, 26, 28, 21, and 18. the scores for four particiopants who completed the test on green paper were 20, 26, 17, and 24. using the .05 level, one-tailed (predicting lower anxiety scores for the yellow paper), what should the researcher colclude? a. use the steps of hypothesis testing
In a study examining the effect of humor on interpersonal attractions, McGee and Shevlin (2009) foundthat a man’s sense of humor had a significant effect onhow he was perceived by women. In the study, femalecollege students were given brief descriptions of a potential romantic partner and then rated the attractivenessof the male on a scale from 1 (low) to 7 (high). Thefictitious male was described positively as being single,ambitious, and having good job prospects. In one condition, the description also said that he had a great senseof humor. The results showed that the description wasrated significantly higher when “a sense of humor” wasincluded. To further examine this effect, a researcherselected a sample of n = 16 college males and askedthem to read a brief description of a female and thenrate the attractiveness of the woman in the description.The description had been used in previous research butwas modified by adding a statement describing a goodsense of humor. Based on the…
In a study examining the effect of humor on interpersonal attractions, McGee and Shevlin (2009) found that a man’s sense of humor had a significant effect on how he was perceived by women. In the study, female college students were given brief descriptions of a potential romantic partner and then rated the attractiveness of the male on a scale from 1 (low) to 7 (high). The fictitious male was described positively as being single, ambitious, and having good job prospects. In one condition, the description also said that he had a great sense of humor. The results showed that the description was rated significantly higher when “a sense of humor” was included. To examine this effect further, a researcher selected a sample of n = 16 college males and asked them to read a brief description of a female and then rate the attractiveness of the woman in the description. The description had been used in previous research but was modified by adding a statement describing a good sense of humor.…