3. • Normal distribution is a
probability distribution
that plots all of its
values in a symmetrical
fashion and most of the
results are
situated around the
probability's mean.
• It is graphically
represented by a
symmetrical bell- shaped
curve that known as the
normal curve.

4. • The curve concentrated
in the center and
decreases on either side.
This means that the data
has less of a tendency to
produce unusually
extreme values, compared
to some other
distributions.
• The bell shaped curve is
symmetric. This tells you
that the probability of
deviations from the mean
is comparable in either
direction.

6. • The standard score is
the distance of the
score from the mean
in terms of the
standard deviations
the observed value lies
above or below the
mean of the
distributions.

7. • Frequencies of scores
in distributions can be
found using the normal
curve. Several
problems on the
different fields can
be solved by applying
the normal curve.

9. Find the z- score of 80
z = - 1.33
= 0.4082 (tabular)

10. 0.50 – 0.4082
= 0.0918 or 9.18%