<span><span>Solve <span>x5 + 3x4 – 23x3 – 51x2 + 94x + 120 </span></span>><span><span> 0</span>. </span></span><span>First, I factor to find the zeroes:<span><span>x5 + 3x4 – 23x3 – 51x2 + 94x + 120</span><span>= (x + 5)(x + 3)(x + 1)(x – 2)(x – 4) = 0</span></span><span>...so </span><span>x = –5, –3, –1, 2,</span><span> and </span>4<span> are the zeroes of this polynomial. (Review how to </span>solve polynomials, if you're not sure how to get this solution.)<span>To solve by the Test-Point Method, I would pick a sample point in each interval, the intervals being </span>(negative infinity, –5)<span>, </span>(–5, –3)<span>, </span>(–3, –1)<span>, </span>(–1, 2)<span>, </span>(2, 4)<span>, and </span>(4, positive infinity). As you can see, if your polynomial or rational function has many factors, the Test-Point Method can become quite time-consuming.<span>To solve by the Factor Method, I would solve each factor for its positivity: </span><span>x + 5 > 0</span><span> for </span><span>x > –5</span>;<span>x + 3 > 0</span><span> for </span><span>x > –3</span><span>; </span><span>x + 1 > 0</span><span> for </span><span>x > –1</span><span>; </span><span>x – 2 > 0</span><span> for </span><span>x > 2</span><span>; and </span><span>x – 4 > 0</span><span> for </span><span>x > 4</span>. Then I draw the grid:...and fill it in:...and solve:<span>Then the solution (remembering to include the endpoints, because this is an "or equal to" inequality) is the set of </span>x-values in the intervals<span> [–5, –3]<span>, </span>[–1, 2]<span>, and </span>[4, positive infinity]</span>. </span>
As you can see, if your polynomial or rational function has many factors, the Factor Method can be much faster.
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For this problem, the most accurate is to use combinations
Because the order in which it was selected in the components does not matter to us, we use combinations
Then the combinations are ![nC_r = \frac{ n! }{r! (n-r)!}](https://tex.z-dn.net/?f=%20nC_r%20%3D%20%5Cfrac%7B%20n%21%20%7D%7Br%21%20%28n-r%29%21%7D%20%20%20)
n represents the amount of things you can choose and choose r from them
You need the probability that the 3 selected components at least one are defective.
That is the same as:
(1 - probability that no component of the selection is defective).
The probability that none of the 3 selected components are defective is:
![P = \frac{_{117}C_3}{_{120}C_3}](https://tex.z-dn.net/?f=%20P%20%3D%20%5Cfrac%7B_%7B117%7DC_3%7D%7B_%7B120%7DC_3%7D%20%20%20)
Where
is the number of ways to select 3 non-defective components from 117 non-defective components and
is the number of ways to select 3 components from 120.
![_{117}C_3 = 260130](https://tex.z-dn.net/?f=%20_%7B117%7DC_3%20%3D%20260130%20%20)
![_{120}C_3 = 280840](https://tex.z-dn.net/?f=%20_%7B120%7DC_3%20%3D%20280840%20%20)
So:
![P = \frac{260130}{280840} = 0.927](https://tex.z-dn.net/?f=%20P%20%3D%20%5Cfrac%7B260130%7D%7B280840%7D%20%3D%200.927%20%20%20)
Finally, the probability that at least one of the selected components is defective is:
![P = 1-0.927 = 0.0737](https://tex.z-dn.net/?f=%20P%20%3D%201-0.927%20%3D%200.0737%20)
P = 7.4%
I think 37%......................................................
Answer:
6 samples
Step-by-step explanation:
Given :
Sample size, = n
Standard deviation, = 6000
Margin of Error = 2000
Confidence interval, α = 95%
Zcritical at 95% = 1.96
n = (Zcritical * σ) / margin of error
n = (1.96 * 6000) /2000
n = 11760 / 2000
n = 5.88
n = 6 samples
P = 4x + 2(x + 5)
That’s the expression
P = perimeter