PS 307 Exam | Questions with complete solutions

PS 307 Exam | Questions with complete solutions A variable for which there is an infinite number of values between any two points on the scale is a ________ variable. a) Discrete b) Ratio c) Continuous d) Confounding A ...

PS 307 Exam | Questions with complete solutions A variable for which there is an infinite number of values between any two points on the scale is a ________ variable. a) Discrete b) Ratio c) Continuous d) Confounding A medical researcher interested in asthma symptoms wanted to know how symptoms were affected in dry versus humid conditions. The researchers recruited 18 asthma patients to spend four weeks under two conditions: sleeping with a dehumidifier for two weeks to create a "dry" environment and sleeping with a humidifier for the remaining two weeks to create a "humid" environment. Patients were asked to rate their symptoms at regular intervals using a scale from "0 - no symptoms" to "20 - maximum asthma symptoms." The change in asthma symptoms from dry to humid conditions was 5.82, showing an advantage for humid conditions. What was the sample in this study? a) change in responses on the scale of 5.82 on average b) four weeks, with two weeks under each condition c) 18 asthma patients d) two sleeping conditions, dry and humid In a between-groups research design, each participant experiences: a) one, and only one, level of the independent variable b) all levels of the independent variable c) one level of the independent variable and the control variable d) measurement before and after exposure to the independent variable A researcher studies year in college, first through fourth year, and its relation to academic motivation. To get the most detail out of her measures, she assesses each student in both the fall and spring semesters of each their four years in school. She finds that students have increasingly higher motivation from their first to fourth year, with a trailing off in the last semester. What is the dependent variable in this study? a) year in school b) semester in school c) academic motivation d) time of year in which the assessment was completed Hypothesis testing refers to: a) drawing conclusions about whether a particular relation between variables is supported by evidence b) the direct manipulation of an independent variable in an attempt to assess its effects on a dependent variable c) summarizing data using descriptive statistics d) measuring a variable of interest using an operational definition What is the correct method for calculating a percentage? a) Divide the total number of participants by the total number of participants in a group and then multiply by 100 b) Divide the total number of participants in a group by the total number of participants and then multiply by 100 c) Subtract the total number of participants in a group from the total number of participants and then multiply by 100 d) Add the total number of participants in all groups and divide by 100 Use the following table to answer this question: This table represents some fictional data for pet ownership. Imagine that pet owners were asked simply, "How many pets live in your home?" Pets, Frequency 1, 42 2, 39 3, 25 4, 16 5, 9 6, 12 7, 5 8, 2 If the average U.S. household has four members, how many pet owners in this sample have more animals than people living in their homes? a) 28 b) 16 c) 9 d) 44 all are correct Use the table below to answer this question: This table represents some fictional data for pet ownership. Imagine that pet owners were asked simply, "How many pets live in your home?" Pets, Frequency 1, 42 2, 39 3, 25 4, 16 5, 9 6, 12 7, 5 8, 2 What percentage of pet owners in this sample have between three and five pets (round to the nearest whole number)? a) 29% b) 33% c) 11% d) 18% A bell-shaped curve is similar to all but which type of distribution? a) symmetric b) normal c) unimodal d) positively skewed Use the graph below to answer this question. Graph description: This polygon represents a fictional distribution of ages for speed-daters. The researcher wanted to know how many people in their 20s attended such events. The polygon shows the number of people ranging in age from 20 to 29. How many speed-daters were 26 years old? a) 5 b) 7 c) 6 d) 4 This figure depicts the results of a study by Ahluwalia et al. (2006) investigating the effects of two types of gum (placebo or nicotine) and two types of counseling (educational or motivational) in helping people to stop smoking. What is the difference between the data depicted in Figure A and the data depicted in Figure B? a) Figure A does not graph the same independent variables as Figure B b) Figure A does not graph the same dependent variable as Figure B c) The bars in Figure A are taller, representing greater proportions, than those in Figure B d) The y-axis in Figure A has been shortened from 1 (which is the highest score possible) to 0.6. This shortening of the scale exaggerates the differences between the groups. The y-axis in Figure A has been shortened from 1 (which is the highest score possible) to 0.6. This shortening of the scale exaggerates the differences between the groups. This figure depicts the results of a study by Shinskey and Munakata (2005) investigating the reaching behavior of seven 5-month-old infants. How many scale independent variables are in this graph? a) none b) 1 c) 2 d) 3 Six students from a statistics class reported the number of hours of television they watch per week. Here are their data: 8, 10, 5, 14, 3, 6. The variance of the number of hours of television watched per week for this sample of six students is: a) 12.89 b) 4.23 c) 6.78 d) 3.59 A unimodal distribution has ________ mode(s). a) two b) two or more c) more than two d) one Sixteen college freshmen were asked to record the number of alcoholic drinks that they typically consume in a week. Here are their data: 2, 4, 6, 0, 1, 10, 9, 0, 6, 3, 6, 8, 5, 4, 6, 2. What is the median number of alcoholic drinks consumed per week? a) 4.0 b) 4.5 c) 5.0 d) 5.5 A researcher analyzed the results of her data and calculated the standard deviation of scores at 3.5. What is the variance? a) 6.88 b) 11.00 c) 12.25 d) 16.00 This table represents the fictional scores of a set of dieters who answered the question "how many times in a week would you estimate you hide your eating behavior (e.g., sneak food, eat in private, under-report consumption)." Table: Hidden Eating Behaviors X, Rating 6, 9 5, 2 4, 5 3, 7 2, 3 1, 21 If the data point 21 is removed from these data, the median changes by a value of _______ whereas the mean changes by a value of _______. a) 1.00; 2.63 b) 3.47; 0.82 c) 2.63; 1.00 d) 0.82; 3.47 Numbers that describe samples are called: a) statistics b) parameters c) averages d) variables Scatterplots are often used to assess what type of pattern the data create. For example, when the data form a pattern that flows upward and toward the right, this is considered to be a(n): a) increasing nonlinear relation b) negative nonlinear relation c) positive linear relation d) negative linear relation A researcher was interested in measuring reaction time differences between men and women on a computerized task. What is the dependent variable? a) researcher b) computerized task c) reaction time d) gender To graph the frequencies of one scale variable, use a: a) scatterplot or line graph b) Pareto chart c) histogram or frequency polygon d) bar graph When calculating the median for an odd number of scores, which have been placed in ascending order, the median will be the: a) middle score b) difference between the highest and lowest scores c) average of the three scores in the middle d) average of the two scores in the middle In a sample of data that has several extremely high scores, creating positive skew, the mean: a) will be less than the mode b) will be greater than the median c) and the mode will be equal d) will be less than the median Jenny hypothesized that older adults would score higher on emotional intelligence measures compared to younger adults in her study. If the results are in support of Jenny's hypothesis, she would: a) reject the alternative hypothesis b) reject the null hypothesis c) accept the null hypothesis d) commit a Type I error The sampling method most likely to lead to a representative sample is: a) random sampling b) convenience sampling c) representative sampling d) volunteer sampling Random samples are almost never used because a) they represent biased views b) we rarely have access to an entire population c) we don't need samples that large d) convenience samples offer better data A(n) ________ refers to the outcome for which we are trying to determine the probability. a) success b) failure c) trial d) outcome Jared, the famous spokesman for the sandwich shop Subway, is an example of ________. While his claims are very impressive and persuasive, a well-designed study would provide more convincing evidence in support of that weight-loss method. a) random selection b) replication c) a testimonial d) personal probability Two events are said to be independent events when: a) the probability of one event is influenced by the occurrence of the other event b) you do not have knowledge about the occurrence of either event c) the probability of one event is determined by the occurrence of the other event d) the probability of one event is not influenced by the occurrence of the other event The expected outcome if an experiment were repeated many, many times is the: a) generalizability b) reliable outcome c) expected relative-frequency probability d) expected outcome The symbol for the population mean is: a) μ b) Σ c) σ d) χ z scores are useful because they: a) allow us to convert raw scores to mean scores, compare scores from different samples, and transform populations into samples b) transform linear scores into nonlinear scores, convert nonlinear scores back into linear scores, and allow us to obtain comparisons between nonlinear and linear scores c) give us an understanding of where a score falls in relation to the mean of its underlying population, allow comparisons to be made between scores from different distributions, and permit the transformation of z scores into percentiles d) reduce the probability of Type I and Type II errors, allow us to compare raw scores with standard scores, and permit the transformation of raw scores into percentiles The ________ forms a symmetrical and mathematically defined bell-shaped pattern. a) asymmetric curve b) unstandardized curve c) normal curve d) nonlinear curve The symbol for the population standard deviation is: a) μ b) Σ c) σ d) χ The second step in converting a z score into a raw score is: a) adding the mean of the population to the product obtained from multiplying the z score and standard deviation b) subtracting the mean of the population from the product obtained by multiplying the z score and standard deviation c) dividing the mean of the population into the product obtained by multiplying the z score and standard deviation d) multiplying the mean of the population and the product obtained from multiplying the z score and standard deviation The subscript M included in the symbols, μM and σM, indicates that a) the mean is the subject b) the values are population parameters c) the values are measures for the sampling distribution of the mean d) the mean of the distribution of means is being presented The pattern of data that is symmetric around a midpoint and fairly accurately predicts reality is called a: a) bell b) skewed distribution c) normal curve d) standardized distribution Of the three assumptions for conducting analyses, which is most likely to be violated because of our use of convenience samples? a) Random selection b) Random assignment c) Normal distribution d) Scale variable assumption Under what conditions is it permissible to proceed with a hypothesis test even though the assumption that the population distribution is approximately normal is violated? a) When we are cautious about generalizing the results b) When we have a sample size greater than 30 c) When the data are not clearly ratio d) When the data are not clearly nominal or ordinal Compared to the standard 5% cutoff for statistical significance, a cutoff of 1% is: a) less conservative b) encouraging of statistical significance c) discouraged by researchers d) more conservative What are the consequences of failing to meet the assumptions of a parametric test when performing research? a) If we fail to meet the assumptions of a parametric test, then we will be unable to make any inferences regarding the population b) If we fail to meet one assumption of a parametric test, then we cannot perform statistical analysis on the results of the study and will be limited to qualitative descriptions of the data c) If we fail to meet even one assumption of a parametric test, then we should perform a nonparametric test instead d) If the test is robust to the violation, it does not invalidate the research; it may, however, make it more difficult to detect effects Imagine that the mean height for all Division I women's basketball programs is 69 inches with a standard deviation of 3 inches. The 2010-2011 women's basketball team at the University of Connecticut, with 10 players listed on the roster, had an average height of 71.2 inches. Using the z statistic, what percent of means would fall below that for these UConn Huskies? a) 98.98% b) 94.98% c) 48.98% d) 86.98% Under what conditions is it permissible to proceed with a hypothesis test even though the assumption that participants are randomly selected is violated? a) When we are cautious about generalizing the results b) We have a sample size greater than 30 c) The data are not clearly ratio d) The data are not clearly nominal or ordinal The mean of the SAT is centered at 500 with a standard deviation of 100 for the population of verbal scores. A sample of 20 participants has a mean of 512. What is the value of the test statistic for this sample and when the sample is increased to 120? a) 12; 1.315 b) 0.537; 1.315 c) 12; 14.4 d) 0.537; 14.4 One of the roles of the researcher performing a meta-analysis is to: a) determine exactly how many studies were never published and find those studies b) throw out statistical outliers from the analysis c) decide on the criteria for the inclusion of studies in the analysis before locating studies d) convince the reader of the existence of the effect of interest If an effect is significant but the effect size for the difference between the two means is small (according to Cohen's conventions), about how much overlap will there be between the two distributions? a) 99% b) 85% c) 50% d) 15% Why are effect sizes rather than test statistics used when comparing study results? a) Using effect sizes, which are not affected by sample size, rather than test statistics, which are influenced by sample size, ensures a fair comparison b) It is easier to average effect size than it is to average test statistics c) Effect size is based on standard error, while test statistics are based on standard deviation d) None of these statements is correct