PSY 230 Final Exam Study Guide ACTUAL
UPDATED Exam Questions and CORRECT
Answers
Joel is interested in the sleeping habits American college students. He interviews a group of 50
students, and finds that these students sleep an average of 6.7 hours per day. The value 6.7 in this
study is an example of ________and American college students are a__________ - CORRECT
ANSWER -Statistic, Population
In a normal distribution, what z-score value separates the lowest 50% of the scores from the rest
of the distribution? - CORRECT ANSWER -Z = 0.00
A bar chart should NOT be used for_____
a. continuous variables
b. ratio level variables
c. interval scales of measurement
d. all of the above - CORRECT ANSWER -d. All of the above
32 degrees Fahrenheit is an example of a value measured on the________ scale of measurement.
- CORRECT ANSWER -interval
A distribution is negatively skewed when_______
a.most of the scores occur at the lower end of the horizontal axis and the curve tails off toward
the higher end
b. it is folded in half and the two sides do not coincide
c. most of the scores occur at the higher end of the horizontal axis and the curve tails off toward
the lower end
d. Both B and C are correct. - CORRECT ANSWER -d. both B and C are correct
, Pearson r coefficient - CORRECT ANSWER -to determine the relationship between two
variables which are measured on different units
Which correlation coefficient shows the strongest relationship between two variables
a. -0.71
b. 0.20
c. -0.10
d. 0.00
e. 0.70 - CORRECT ANSWER -a. -0.71
The closer the points on a scatter diagram fall to the regression line, the________ between the
scores - CORRECT ANSWER -Stronger the correlation
The proportion of variance accounted fir by a correlation between 2 variables is determined
by_____ - CORRECT ANSWER -r^2
Pearson r is the slope of the least squares regression line when the scores are plotted as Z scores.
True or False? - CORRECT ANSWER -True
If the sample data produce a test statistics (Z-obt) that is in the critical region, then which of the
following is the appropriate conclusion for the test? - CORRECT ANSWER -reject Ho
Researchers want the statistical power of the test to be relatively high (at least .80) because this
will: - CORRECT ANSWER -Increase the probability that a false null hypothesis will be
rejected (decrease type 2 error)
To ethically increase the probability of rejecting Ho you should____ - CORRECT
ANSWER -use the most powerful test
The following factors all affect power EXCEPT:
UPDATED Exam Questions and CORRECT
Answers
Joel is interested in the sleeping habits American college students. He interviews a group of 50
students, and finds that these students sleep an average of 6.7 hours per day. The value 6.7 in this
study is an example of ________and American college students are a__________ - CORRECT
ANSWER -Statistic, Population
In a normal distribution, what z-score value separates the lowest 50% of the scores from the rest
of the distribution? - CORRECT ANSWER -Z = 0.00
A bar chart should NOT be used for_____
a. continuous variables
b. ratio level variables
c. interval scales of measurement
d. all of the above - CORRECT ANSWER -d. All of the above
32 degrees Fahrenheit is an example of a value measured on the________ scale of measurement.
- CORRECT ANSWER -interval
A distribution is negatively skewed when_______
a.most of the scores occur at the lower end of the horizontal axis and the curve tails off toward
the higher end
b. it is folded in half and the two sides do not coincide
c. most of the scores occur at the higher end of the horizontal axis and the curve tails off toward
the lower end
d. Both B and C are correct. - CORRECT ANSWER -d. both B and C are correct
, Pearson r coefficient - CORRECT ANSWER -to determine the relationship between two
variables which are measured on different units
Which correlation coefficient shows the strongest relationship between two variables
a. -0.71
b. 0.20
c. -0.10
d. 0.00
e. 0.70 - CORRECT ANSWER -a. -0.71
The closer the points on a scatter diagram fall to the regression line, the________ between the
scores - CORRECT ANSWER -Stronger the correlation
The proportion of variance accounted fir by a correlation between 2 variables is determined
by_____ - CORRECT ANSWER -r^2
Pearson r is the slope of the least squares regression line when the scores are plotted as Z scores.
True or False? - CORRECT ANSWER -True
If the sample data produce a test statistics (Z-obt) that is in the critical region, then which of the
following is the appropriate conclusion for the test? - CORRECT ANSWER -reject Ho
Researchers want the statistical power of the test to be relatively high (at least .80) because this
will: - CORRECT ANSWER -Increase the probability that a false null hypothesis will be
rejected (decrease type 2 error)
To ethically increase the probability of rejecting Ho you should____ - CORRECT
ANSWER -use the most powerful test
The following factors all affect power EXCEPT:
