<s>
In	O
statistics	O
,	O
the	O
interdecile	B-General_Concept
range	I-General_Concept
is	O
the	O
difference	O
between	O
the	O
first	O
and	O
the	O
ninth	O
deciles	O
(	O
10%	O
and	O
90%	O
)	O
.	O
</s>
<s>
The	O
interdecile	B-General_Concept
range	I-General_Concept
is	O
a	O
measure	O
of	O
statistical	O
dispersion	O
of	O
the	O
values	O
in	O
a	O
set	O
of	O
data	O
,	O
similar	O
to	O
the	O
range	B-General_Concept
and	O
the	O
interquartile	B-General_Concept
range	I-General_Concept
,	O
and	O
can	O
be	O
computed	O
from	O
the	O
(	O
non-parametric	O
)	O
seven-number	O
summary	O
.	O
</s>
<s>
Despite	O
its	O
simplicity	O
,	O
the	O
interdecile	B-General_Concept
range	I-General_Concept
of	O
a	O
sample	O
drawn	O
from	O
a	O
normal	O
distribution	O
can	O
be	O
divided	O
by	O
2.56	O
to	O
give	O
a	O
reasonably	O
efficient	O
estimator	O
of	O
the	O
standard	B-General_Concept
deviation	I-General_Concept
of	O
a	O
normal	O
distribution	O
.	O
</s>
<s>
This	O
is	O
derived	O
from	O
the	O
fact	O
that	O
the	O
lower	O
(	O
respectively	O
upper	O
)	O
decile	O
of	O
a	O
normal	O
distribution	O
with	O
arbitrary	O
variance	O
is	O
equal	O
to	O
the	O
mean	O
minus	O
(	O
respectively	O
,	O
plus	O
)	O
1.28	O
times	O
the	O
standard	B-General_Concept
deviation	I-General_Concept
.	O
</s>
<s>
A	O
more	O
efficient	O
estimator	O
is	O
given	O
by	O
instead	O
taking	O
the	O
7%	O
trimmed	O
range	B-General_Concept
(	O
the	O
difference	O
between	O
the	O
7th	O
and	O
93rd	O
percentiles	O
)	O
and	O
dividing	O
by	O
3	O
(	O
corresponding	O
to	O
86%	O
of	O
the	O
data	O
falling	O
within	O
±	O
1.5	O
standard	B-General_Concept
deviations	I-General_Concept
of	O
the	O
mean	O
in	O
a	O
normal	O
distribution	O
)	O
;	O
this	O
yields	O
an	O
estimator	O
having	O
about	O
65%	O
efficiency	O
.	O
</s>
<s>
Analogous	O
measures	O
of	O
location	O
are	O
given	O
by	O
the	O
median	O
,	O
midhinge	B-General_Concept
,	O
and	O
trimean	O
(	O
or	O
statistics	O
based	O
on	O
nearby	O
points	O
)	O
.	O
</s>
