Answer:
0 is the probability that Tim will select a card labeled with a number 6.
Step-by-step explanation:
We are given the following in the question:
Number of cards = 4
Cards with labels:
1,3,5,7
Tim will select one card from the box. We have to find the probability that Tim will select a card labeled with a number 6.
Formula:
0 is the probability that Tim will select a card labeled with a number 6. Thus, it is an impossible event.
Answer:
Step-by-step explanation:
3(a+3)-6=21
<=>3a+9-6=21
<=>3a+3=21
<=>3a=18
<=>a=6
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:
Margin of error of 0.0485 hours.
Step-by-step explanation:
We have that to find our 
level, that is the subtraction of 1 by the confidence interval divided by 2. So:
Now, we have to find z in the Ztable as such z has a pvalue of 
.
That is z with a pvalue of 
, so Z = 1.96.
Now, find the margin of error M as such
In which 
is the standard deviation of the population and n is the size of the sample.
In this question:
The margin of error is of:
Margin of error of 0.0485 hours.
All but the last one I think but don't quote me
