-

Your In Autocorrelation Days or Less

For example, if

X

=

(

X
great site
1

,

X

2

this ,

X

3

)

check my site T

{\displaystyle \mathbf {X} =\left(X_{1},X_{2},X_{3}\right)^{\rm {T}}}

is a random vector, then

R

X

X

{\displaystyle \operatorname {R} _{\mathbf {X} \mathbf {X} }}

is a

3

3

{\displaystyle 3\times 3}

matrix whose

(
i
,
j
)

{\displaystyle (i,j)}

-th entry is

E

[

X

i

X

j

]

{\displaystyle \operatorname {E} [X_{i}X_{j}]}

. .