Looks like a badly encoded/decoded symbol. It's supposed to be a minus sign, so you're asked to find the expectation of 2<em>X </em>² - <em>Y</em>.
If you don't know how <em>X</em> or <em>Y</em> are distributed, but you know E[<em>X</em> ²] and E[<em>Y</em>], then it's as simple as distributing the expectation over the sum:
E[2<em>X </em>² - <em>Y</em>] = 2 E[<em>X </em>²] - E[<em>Y</em>]
Or, if you're given the expectation and variance of <em>X</em>, you have
Var[<em>X</em>] = E[<em>X</em> ²] - E[<em>X</em>]²
→ E[2<em>X </em>² - <em>Y</em>] = 2 (Var[<em>X</em>] + E[<em>X</em>]²) - E[<em>Y</em>]
Otherwise, you may be given the density function, or joint density, in which case you can determine the expectations by computing an integral or sum.
Answer:
B
Step-by-step explanation:
since y and x vary directly the equation relating them is
y = kx ← k is the constant of variation
to find k use any ordered pair from the list given
using x = 4 when y = - 2, then
k =
=
= - 0.5 → B
1 kilometer equal .62 miles.
Answer: Hope this helps
Step-by-step explanation: Listen, exponents may be complicated at first but
The basic concept is to think of it like 2 to the 3rd power would be 2x2x2
since you are multiplying the number by itself three times