EXAM 2 QUESTIONS AND CORRECT
ANSWERS
positively (right) skewed distribution ANSW✅✅majority at lower values, outlier at high values
positively (right) skewed distribution mean, median and mode ANSW✅✅increasing order: mode--
>median-->mean
central tendency ANSW✅✅a single value that describes the middle of the distribution
measures of central tendency ANSW✅✅mean, median, mode
mean ANSW✅✅the arithmetic average of a set of scores
population mean symbol ANSW✅✅μ
sample mean symbol ANSW✅✅x̅ or M
The mean is calculated by... ANSW✅✅adding up all the values in a distribution and dividing by the
number of scores
formula for the population mean ANSW✅✅μ=ΣX/N
μ= population mean
Σ= "sum of"
X= score
N= population size
ΣX= the sum of all scores
formula for the sample mean ANSW✅✅x̅=ΣX/n
, x̅= sample mean
ΣX= sum of all scores
n= sample size
The mean is the preferred measure of central tendency if the distribution is...
ANSW✅✅symmetrical
The mean can be influences by... ANSW✅✅outliers
outliers ANSW✅✅extreme values in a dataset
The mean may not be appropriate when there are... ANSW✅✅outliers
median ANSW✅✅the midpoint of a distribution of scores; may be more appropriate to use when
there are outliers
____% of scores fall above the median and ____% of scores fall below the median.
ANSW✅✅50;50
How to calculate median when there is an odd number of scores? ANSW✅✅arrange scores in
ascending order and identify the middle value
How to calculate median when there is an even number of scores? ANSW✅✅arrange scores in
ascending order and take the average of the 2 middle values
Is the median affected by outliers? ANSW✅✅no
The median is preferred when... ANSW✅✅the distribution contains extreme scores or is skewed
or variables measured on an ordinal scale
mode ANSW✅✅the most common score in a dataset