Question 1173973
Describe four characteristics of a normal distribution
I.  symmetric:  Right side of center is a mirror image of the left side
II. unimodal:   There is only one peak    
III. asymptotic:  distribution is continuous & tails that approach the x-axis, but do not touch it.
IV.  the mean, median, and mode are all equal.
 Below is an example of a Normal distribution with mean = 0, sd = 1  
with the z-scores as they relate to the distribution of values
{{{drawing(400,200,-5,5,-.5,1.5, graph(400,200,-5,5,-.5,1.5, exp(-x^2/2)), green(line(1,0,1,exp(-1^2/2)),line(-1,0,-1,exp(-1^2/2))),green(line(2,0,2,exp(-2^2/2)),line(-2,0,-2,exp(-2^2/2))),green(line(3,0,3,exp(-3^2/2)),line(-3,0,-3,exp(-3^2/2))),green(line( 0,0, 0,exp(0^2/2))),locate(4.8,-.01,z),locate(4.8,.2,z))}}}
For the normal distribution: 
one  standard deviation from the mean accounts for about 68.2% of the set 
two standard deviations from the mean account for about 95.4%
and three standard deviations from the mean account for about 99.7%.