Chapter 12.2: Distributions
if one peak is higher than the other in a bimodal distribution graph how many modes are there
1
approximately _____ of the distribution is within one standard deviation of the mean on a normal distribution curve
68%
approximately _____ of the distribution is within two standard deviations of the mean on a normal distribution curve
95%
approximately ____ of the distribution is within three standard deviations of the mean on a normal distribution curve
99%
a distribution containing two peaks with a valley in between
bimodal distribution
have multiple peaks, although not necessarily multiple modes, strictly speaking, it may be useful to perform data analysis on the two group separately
bimodal distributions
the mean, median, and mode are at the ____ of distribution
center
in a positively skewed distribution curve is the mean higher or lower than the median
higher
a negatively skewed distribution has a tail on the _____ side
left
in a negatively skewed distribution curve is the mean higher or lower than the median
lower
a _____ skewed distribution has a tail on the left (negative) side
negatively
the ______ distribution is symmetrical
normal
A function that represents the distribution of variables as a symmetrical bell-shaped graph
normal distribution
the basis for the bell curve
normal distribution
a _____ skewed distribution has a tail on the right (positive) side
positively
types of skewed distribution curves
positively skewed negatively skewed
a positively skewed distribution has a tail on the _____ side
right
when the two peaks are separated by a sufficient distance (only a small amount of data within the valley regions) the bimodal regions can be analyzed ______
separately
have differences in their mean, median, and mode; contains a tail on one side of the other of the data set *the tail is what determines the direction not the bulk of the graph
skewed distribution
a normal distribution with a mean of zero and a standard deviation of one
standard distribution
How do the mean, median, and mode compare for a right-skewed distribution?
the mean is higher than the median which is higher than the mode
the mean, median, and mode, are _____ in normal distribution
the same
on the MCAT skewed distributions are tested by simply identifying their; the visual shift on the graph is OPPOSITE the direction of the skew
type
Can data that do not follow a normal distribution be analyzed with measures of central tendency and measures of distribution?
yes, they still have mean medians and modes (for skewed and bimodal)