Properties of Normal Distribution
a.It is a continuous probability distribution having parameters m and .
b.The normal curve is perfectly symmetrical about the mean (m) and is bell shaped. It means that if we fold the curve along the vertica line at the centre the two halves of the curve would coincide. The two tails of the curve on either side of x = m extends to infinity.
c.Mean = Median = Mode skewness = 0.
d.It has only one mode.
e.Q1 and Q3 are equidistant from median or mean.
Q1 = m - 0.67 Q3 = m +0.67 (app)
Quartile Deviation = 0.67 mean deviation (about mean) = 0.80= 4/ 5.
f.The maximum ordinate is at x= m its vlaues1/ √2λ.
g.The area under the curve means the area lying between the curve and the horizontal axis and is equal to the number of frequencies. The s distributes this area as follows.