Answer:
10
Step-by-step explanation:
-80 / -8 = 10
the negatives cancel each other out
Answer:
23-5= 18
Step-by-step explanation:
Step-by-step explanation:
Step 1: Multiply the 2 with the X to get 2X.
Step 2: multiply the 2 with the 4 and get 8
Step 3: your answer is 2X+8
Answer:
Step-by-step explanation:
<u>Given:</u>
<u>Find z-score:</u>
- z = (x - μ)/σ
- z = (104 - 80)/12 = 2
Percent value corresponding to 2 as per z-table is 0.9772. This is corresponding to 97.72%.
<u>Percentage of students earned more than $104:</u>
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.
