Statistics Final Exam

What is the median for the following set of scores? Scores: 1, 5, 11, 12, 20

11

What is the value of SS (sum of squared deviations) for the following population? Population: 1, 1, 1, 5

12

A sample consists of n = 16 scores. How many of the scores are used to calculate the range?

2 scores

A sample of n = 12 scores ranges from a high of X = 7 to a low of X = 4. If these scores are placed in a frequency distribution table, how many X values will be listed in the first column?

4

The sum of the squared deviation scores is SS = 50 for a population of N = 10 scores. What is the variance for this population?

5

What is the mean for the following sample of scores? Scores: 2, 4, 5, 9

5

Why do deviation scores have to be squared before calculating the standard deviation?

If deviation scores are not squared, then the average distance from the mean will always equal 0.

The sum of the squared deviation scores is 20 for 6 scores. What is the variance?

It cannot be answered without additional information

After 2 points are subtracted from every score in a sample of size n = 4, the new sample mean is found to be M = 18. What was the mean for the original sample?

M= 20

A sample of n = 6 scores has a mean of M = 5. One person with a score of X = 19 is added to the distribution. What is the mean for the new set of scores?

M= 7

In a frequency distribution graph, frequencies are presented on the _____ and the scores (categories) are listed on the _____.

Y axis; X axis

A researcher surveys a sample of n = 10 adults and asks them to indicate their favorite day of the week. If the data were organized in a frequency distribution table, what would be included in the first column?

a list of days of the week

The main distinction between an interval and ratio scale of measurement is that _____.

a score of 0 on a ration scale represents the complete absence of that variable

Consider the distribution of exam scores for the first exam within a college course. If the set of exam scores forms a symmetrical distribution (bell-curve like), what can be concluded about the students' scores?

about an equal number of students had relatively high and relatively low scores

For the following grouped frequency distribution table of exam scores, what is the lowest score on the exam? X 90-99 80-89 70-79 60-69 50-59 f 3 1 2 3 4

cannot be determined

Which of the following actions will always change the value of the mean?

changing the value of one score

Which of the following is a critical unique aspect of the experimental method?

manipulation of one variable

The mode is the only measure of central tendency that is appropriate to utilize for a variable measured with which scale of measurement?

nominal

A researcher is curious about the average monthly car insurance bill for high school students in the state of Florida. If this average could be obtained, it would be an example of a _____.

parameter

A researcher uses an anonymous survey to investigate the television-viewing habits of 100 American adolescents. The researcher plans to make an inference about the television-viewing habits of all American adolescents based on the results of the survey. The entire group of American adolescents is an example of a _____.

population

The students in a psychology class seem to think that the midterm exam was very difficult. If they are correct, what is the most likely shape for the distribution of exam scores?

positively skewed

The average verbal SAT score for the entire class of incoming college freshmen in the United States is 530. However, if a sample of 20 incoming college freshmen is randomly selected from the United States, it is likely that this sample's average verbal SAT score will not be exactly 530. This is consistent with the concept of _____.

sampling error

Lauren is a psychologist interested in whether observing helpful actions while consuming media causes greater future helping behavior. She designs a research study in which one group of participants watch a pleasant television show depicting people helping others for 20 minutes, whereas a second group of participants watch a pleasant television show for 20 minutes where no helping behavior takes place. After watching the show assigned to them, participants in each group are then provided the opportunity to help another student who drops a folder of papers, and Lauren records whether each participant helps this other student or not. In this research study, the control condition is _____.

the group of participants who watch the pleasant television show for 20 mins where no helping behavior takes place

A population of N = 6 scores has ΣX = 42. What is the population mean?

µ = 7