<s>
In	O
time	O
series	O
analysis	O
,	O
a	O
fan	B-Application
chart	I-Application
is	O
a	O
chart	O
that	O
joins	O
a	O
simple	O
line	B-Application
chart	I-Application
for	O
observed	O
past	O
data	O
,	O
by	O
showing	O
ranges	O
for	O
possible	O
values	O
of	O
future	O
data	O
together	O
with	O
a	O
line	O
showing	O
a	O
central	O
estimate	O
or	O
most	O
likely	O
value	O
for	O
the	O
future	O
outcomes	O
.	O
</s>
<s>
The	O
term	O
"	O
fan	B-Application
chart	I-Application
"	O
was	O
coined	O
by	O
the	O
Bank	O
of	O
England	O
,	O
which	O
has	O
been	O
using	O
these	O
charts	O
and	O
this	O
term	O
since	O
1997	O
in	O
its	O
"	O
Inflation	O
Report	O
"	O
to	O
describe	O
its	O
best	O
prevision	O
of	O
future	O
inflation	O
to	O
the	O
general	O
public	O
.	O
</s>
<s>
Fan	B-Application
charts	I-Application
have	O
been	O
used	O
extensively	O
in	O
finance	O
and	O
monetary	O
policy	O
,	O
for	O
instance	O
to	O
represent	O
forecasts	O
of	O
inflation	O
.	O
</s>
<s>
In	O
this	O
case	O
,	O
inflation	O
forecast	O
fan	B-Application
charts	I-Application
are	O
usually	O
accompanied	O
with	O
the	O
balance	O
of	O
risks	O
,	O
the	O
probability	O
that	O
the	O
future	O
inflation	O
falls	O
below	O
its	O
modal	O
forecast	O
.	O
</s>
<s>
Therefore	O
,	O
the	O
fan	B-Application
chart	I-Application
ranges	O
depend	O
on	O
these	O
parameters	O
only	O
.	O
</s>
