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)