Select all the properties that must be true of a normal distribution. a
The distribution is bell-shaped.
b
The distribution is determined by the mean and standard deviation.
c
The distribution has a height of zero when it is more than 3 standard deviations away from the center.
d
The distribution is centered at the mean absolute deviation.
e
The total area under the normal distribution curve is 1.
f
The area under the normal distribution curve and within 2 standard deviations of the center is about 95% of the total area under the curve.