3070K Exam 1

A class exam has a mean of 75 and a standard deviation of 10. The standard deviation means that the grades in the sample deviate, on average,

10 points from the mean

A researcher was interested in the side effects of gender on attitudes toward women in leadership positions. The researcher surveyed a group of individuals, 12 of whom were men and 12 of whom were women. In this example, MEN is:

a level of the predictor variable

Which measure of central tendency is most appropriate to identify the most typical choice of a major at your college?

mode

Prof Kellogg calculates the grades on the first exam for her stats class. She finds that students did really well, with most students scoring 98 or higher. How would the distribution be shaped?

negative skew

The measurement of the performance of runners in a race based on their finishing places is a(n) ______ variable. The measurement of the performance of the runners in a race based on their times to complete the race is a(n) ______ variable.

ordinal/ratio

A researcher was interested in the side effects of gender on attitudes toward women in leadership positions. The researcher surveyed a group of individuals, 12 of whom were men and 12 of whom were women. What type of study best describes this research?

quasi experiment

A counseling center director wanted to compare the length of therapy in weeks for students who came in for treatment for depression vs students who came in for treatment for anxiety. She wanted to report these data to the university admins to help develop next years budget. What research technique or techniques would be possible and appropriate?

random selection but not random assignment

On a histogram, the x axis depicts the values of ______ variable, but on a bar graph the x axis depicts the values of ______ variable.

scale/nominal

If a sample variance is computed by dividing SS by n, then the average value of the sample variance from all the possible random samples will be ______ the population variance.

smaller than

Numbers that describe samples are called ______ , and numbers that describe populations are called ______ .

statistics/parameters

For an experiment comparing two methods for teaching social skills to autistic children, the independent variable is ______ and the dependent variable is ______.

teaching methods/the social skills learned

You have a score of X=65 on an exam. which set of parameters would give you the best grade on the exam?

u=60 and o=5

For a particular sample, the largest distance (deviation) between a score and the mean is 11 points. The smallest distance between a score and the mean is 4 points. Therefore, the standard deviation

will be between 4 and 11

Hsee and Tang (2007) reported the results of a study in which 195 college students completed a happiness scale (from 1 to 7) just before taking a midterm exam. On this scale, 1 corresponded to very unhappy and 7 to very happy. On average, the students rated their happiness as 6.18. In this study, which of the following would require an inferential statistic?

The conclusion that college students, on average, are rather happy prior to taking midterm exams

An elementary school teacher is interested in the relation between sugar consumption and activity level in preschool children. The teacher gives 30 preschool children from Preppy Preschool Playland 0 milligrams, 20 milligrams, or 50 milligrams of sucrose in a breakfast drink. She then observes their behavior for 30 minutes during their morning outdoor play period and codes their activity level. In this example, the population is ______ and the sample is ______.

all preschool children/30 preschool children

In a study assessing the influence of self esteem on romantic attraction, the researchers stated that they manipulated self esteem by either insulting or complimenting students about their physical appearance just before they went on a blind date. The researchers' statement of how they manipulated self esteem is

an operational definition

Prof. Martin was interested in which of two popular statistics textbooks (Statistics: It Will Change Your Life and Statistics: Bigger, Better and Stronger) was better for students. Prof. Martin compared the two textbooks by assigning one text to one section of statistics taught by Prof. Miller from 10-11am MWF and the other text to a section of stats taught by Prof. Mervin from 7-10pm on Weds. evenings. At the end of the term, all students took the same comprehensive test. Students to whom Statistics: Bigger, Better, and Stronger was assigned performed better on the test than did students to whom Statistics: It Will Change Your Life was assigned. Therefore, Prof. Martin concluded that the former textbook was the better one. Which of the following is NOT a potential cofounding variable in this study? - number of classes per week -professors teaching course -comprehensive test scores -time of day course is taught

comprehensive test scores

If a few extreme outliers are added to a data set, the standard deviation most likely will

increase

In a population of N=6, five of the individuals all have scores that are exactly 1 point above the mean. From this information, what can you determine about the score for the sixth individual?

it is below the mean by 5 points

For a negatively skewed distribution with a mode of X = 25 and a median of 20, what is the most likely value for the mean?

less than 20

Each of the US states has a certain number of miles of ocean coastline (ranging from 1 to 6640 miles). Consider a frequency distribution of these 50 scores. What central tendency statistic is appropriate for this distribution?

median