pbsi 301 benchmark

of these 3, which of the following is the most common goal in statistics:

- generalize results from a population to a second population

- generalize results from a population to a sample

- generalize results from a sample to a population

- generalize results from a sample to a population

the measure of central tendency most influenced by outliers is the _____

mean

what summary statistic reflects the amount of variability in a dataset?

standard deviation

which of the following scores has the greatest variability:

- 7, 7, 7, 7, 7

- 7, 10, 11, 15, 19

- 6, 6, 7, 7 ,7

- 7, 10, 11, 15, 19

what is the term associated with the lack of symmetry in a distribution?

skewness

which of the following statements about reliability and validity are true:

- high reliability automatically guarantees high validity

- it is possible to have a reliability without validity

- validity sets the upper bound of reliability

- it is possible to have a reliability without validity

what assumption should be made until there is sufficient evidence otherwise?

the null hypothesis is true

what values are most likely to be seen in a normal distribution?

values very close to the mean

in hypothesis testing, the test statistic (obtained value) must be compared against the ____

critical value

the level of significance (alpha) is determined by ______

the researchers

what action should you take if the obtained value exceeds the critical value?

reject the null hypothesis

what is the term used to describe the ability of a statistical test to detect and reject a null hypothesis when it is false?

power

what is true about the significance of this statistic, t-test, t = 1.42, p > 0.05?

there is not a significant differences between the two groups

Dr. Moo would like to find out if there was a significant difference between male and female patient's anxiety scores. what is the appropriate test to run?

independent t-test

an instructor administers a baseline exam to his class on the first day of the semester and then administers the same exam to the class 10 weeks later. which would be the most appropriate choice of statistical procedure to analyze the data to investigate the improvement in scores from the pretest to the posttest?

dependent t-test

if you want to examine the difference between the average scores of the three unrelated groups, which statistical techniques should you select?

ANOVA

which example of a factorial design that examines the effects of region of residence (northwest, south, midwest, and west) and income (low, medium, high)?

4x3 ANOVA

in factorial ANOVA, the number of potential main effects is equal to the number of _____

independent variables

the statement rxy =/= 0 represents _____

a research hypothesis

Which of the following statements is an example of a negative correlational relationship?

- Children who are rewarded for good behavior will grow up to lead productive lives

- Teenagers who work more hours (i.e., employment) have lower grades

- Delinquent children are likely to become adult criminal offenders

Teenagers who work more hours (i.e., employment) have lower grades

which of the following has the strongest correlation?

- 0.21

- -0.92

- 0.85

- -0.92

If a researcher wants to know whether income is associated with crime, he or she may be reluctant to collect data from a poor part of town that has a high crime rate. As a result, the data would not include very low income levels and the correlation coefficient would be lower than if such data were included. The potential problem in this case is _____

restriction of range

what does an r-squared (coefficient determination) value of 0.25 indicate in the context of correlation?

about 25% of the data's variability is explained by the variable's relationship

what is the distance between each data point and the regression line called?

residual

a researcher is investigating whether there is an association between gender (males or females) and smoking status (smokers and non-smokers) in a sample of 500 participants. which test would be the most appropriate for analyzing this data?

chi-square test