iv) Area from -2.18 to - 1.35 is the same from 1.35 to 2.18.
P ( -2.18 £
z £
-1.35 ) = 0.4854 - 0.4115
= 0.0739 i.e. »
7% of area.
v) Required area = 0.5 - Area between z = 0 to z = 0.6
(to the left of -0.6)
= 0.5 - P ( o
£
z £
0.6 )
= 0.5 - ( 0.2257 )
= 0.2743 »
27% of area.
vi) Required area = (Area between z = 0 and z = -1.28) + 0.5
=
(Area between z = 0 and z = -1.28) + 0.5
=
0.3997 + 0.5
=
0.8997 » 90% of area.
vii) Area from - 2.18 to 0 is the same as
from 0 to 2.18 which is
P ( -2.18 £ z £ 0 )
= P ( 0 £ z £ -2.18) = 0.4864
and area from 0 to 1.35 is
P ( 0 £ z £ -1.35) = 0.4115
Thus the required area is the sum of two
i.e. P (-2.18 £ z £ -1.35) = 0.4854 + 0.4115
= 0.8969 » 90% of area
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