The expected length of code for one encoded symbol is

where
is the probability of picking the letter
, and
is the length of code needed to encode
.
is given to us, and we have

so that we expect a contribution of

bits to the code per encoded letter. For a string of length
, we would then expect
.
By definition of variance, we have
![\mathrm{Var}[L]=E\left[(L-E[L])^2\right]=E[L^2]-E[L]^2](https://tex.z-dn.net/?f=%5Cmathrm%7BVar%7D%5BL%5D%3DE%5Cleft%5B%28L-E%5BL%5D%29%5E2%5Cright%5D%3DE%5BL%5E2%5D-E%5BL%5D%5E2)
For a string consisting of one letter, we have

so that the variance for the length such a string is

"squared" bits per encoded letter. For a string of length
, we would get
.
Answer:

Step-by-step explanation:
This equation can simply be solved by adding 15 to both sides.
To graph, draw a closed point at the center of the line and darken the area to the right of it.
Answer:
Step-by-step explanation:
A, B & C lie on a straight line.
D, C & E lie on a different straight line.
Ah, this is 2 intersecting lines
angles
y
= 106° and angle
z
= 64°.
well we know that a full size of circle is 360 degrees
let's add z and y :
106+64 = 170
then, let's subtract it from 360
360 - 170 = 90
we must devide it by 2, why? because 90 is from two section of x (2x)
so 90/2 = 45
and there you have it x = 45
if you still cannot visualize what is intersecting line mean, then see the file below
Answer:
First, you must find the midpoint of the segment, the formula for which is
(
x
1
+
x
2
2
,
y
1
+
y
2
2
)
. This gives
(
−
5
,
3
)
as the midpoint. This is the point at which the segment will be bisected.
Next, since we are finding a perpendicular bisector, we must determine what slope is perpendicular to that of the existing segment. To determine the segment's slope, we use the slope formula
y
2
−
y
1
x
2
−
x
1
, which gives us a slope of
5
.
Perpendicular lines have opposite and reciprocal slopes. The opposite reciprocal of
5
is
−
1
5
.
We now know that the perpendicular travels through the point
(
−
5
,
3
)
and has a slope of
−
1
5
.
Solve for the unknown
b
in
y
=
m
x
+
b
.
3
=
−
1
5
(
−
5
)
+
b
⇒
3
=
1
+
b
⇒
2
=
b
Therefore, the equation of the perpendicular bisector is
y
=
−
1
5
x
+
2
.
Related questions
What is the midpoint of the line segment joining the points (7, 4) and (-8, 7)?
How would you set up the midpoint formula if only the midpoint and one
Step-by-step explanation: