Answer: C) 133
Step-by-step explanation:
The formula to find the sample size is given by :-
![n=(\dfrac{z^*\cdot\sigma}{E})^2](https://tex.z-dn.net/?f=n%3D%28%5Cdfrac%7Bz%5E%2A%5Ccdot%5Csigma%7D%7BE%7D%29%5E2)
, where z* = Critical z-value
= Population standard deviation for prior study.
E= Margin of error.
As per given , we have
E= 5
The critical z-value for 90% confidence level is 1.645.
Substitute al;l the value sin the above formula , we get
![n=(\dfrac{1.645\times 35}{5})^2](https://tex.z-dn.net/?f=n%3D%28%5Cdfrac%7B1.645%5Ctimes%2035%7D%7B5%7D%29%5E2)
![n=(\dfrac{57.575}{5})^2](https://tex.z-dn.net/?f=n%3D%28%5Cdfrac%7B57.575%7D%7B5%7D%29%5E2)
![n=(11.515)^2](https://tex.z-dn.net/?f=n%3D%2811.515%29%5E2)
![n=132.595225\approx133](https://tex.z-dn.net/?f=n%3D132.595225%5Capprox133)
Hence, the minimum sample size needed is 133.
Thus , the correct answer is : C) 133
Answer:
y = 20°
x = 35°
Explanation:
Equation's:
1) 2y + x + 105° = 180°
2) 3x + x + 2y = 180°
Make y subject in equation 2
3x + x + 2y = 180
4x + 2y = 180
2y = 180 - 4x
y = 90 - 2x
Insert this into equation 1
2(90 - 2x) + x + 105° = 180°
180 - 4x + x + 105 = 180
-3x = -105
x = 35°
Find value of y
y = 90 - 2x
y = 90 - 2(35)
y = 20°
There's nothing preventing us from computing one integral at a time:
![\displaystyle \int_0^{2-x} xyz \,\mathrm dz = \frac12xyz^2\bigg|_{z=0}^{z=2-x} \\\\ = \frac12xy(2-x)^2](https://tex.z-dn.net/?f=%5Cdisplaystyle%20%5Cint_0%5E%7B2-x%7D%20xyz%20%5C%2C%5Cmathrm%20dz%20%3D%20%5Cfrac12xyz%5E2%5Cbigg%7C_%7Bz%3D0%7D%5E%7Bz%3D2-x%7D%20%5C%5C%5C%5C%20%3D%20%5Cfrac12xy%282-x%29%5E2)
![\displaystyle \int_0^{1-x}\int_0^{2-x}xyz\,\mathrm dz\,\mathrm dy = \frac12\int_0^{1-x}xy(2-x)^2\,\mathrm dy \\\\ = \frac14xy^2(2-x)^2\bigg|_{y=0}^{y=1-x} \\\\= \frac14x(1-x)^2(2-x)^2](https://tex.z-dn.net/?f=%5Cdisplaystyle%20%5Cint_0%5E%7B1-x%7D%5Cint_0%5E%7B2-x%7Dxyz%5C%2C%5Cmathrm%20dz%5C%2C%5Cmathrm%20dy%20%3D%20%5Cfrac12%5Cint_0%5E%7B1-x%7Dxy%282-x%29%5E2%5C%2C%5Cmathrm%20dy%20%5C%5C%5C%5C%20%3D%20%5Cfrac14xy%5E2%282-x%29%5E2%5Cbigg%7C_%7By%3D0%7D%5E%7By%3D1-x%7D%20%5C%5C%5C%5C%3D%20%5Cfrac14x%281-x%29%5E2%282-x%29%5E2)
![\displaystyle\int_0^1\int_0^{1-x}\int_0^{2-x}xyz\,\mathrm dz\,\mathrm dy\,\mathrm dx = \frac14\int_0^1x(1-x)^2(2-x)^2\,\mathrm dx](https://tex.z-dn.net/?f=%5Cdisplaystyle%5Cint_0%5E1%5Cint_0%5E%7B1-x%7D%5Cint_0%5E%7B2-x%7Dxyz%5C%2C%5Cmathrm%20dz%5C%2C%5Cmathrm%20dy%5C%2C%5Cmathrm%20dx%20%3D%20%5Cfrac14%5Cint_0%5E1x%281-x%29%5E2%282-x%29%5E2%5C%2C%5Cmathrm%20dx)
Expand the integrand completely:
![x(1-x)^2(2-x)^2 = x^5-6x^4+13x^3-12x^2+4x](https://tex.z-dn.net/?f=x%281-x%29%5E2%282-x%29%5E2%20%3D%20x%5E5-6x%5E4%2B13x%5E3-12x%5E2%2B4x)
Then
![\displaystyle\frac14\int_0^1x(1-x)^2(2-x)^2\,\mathrm dx = \left(\frac16x^6-\frac65x^5+\frac{13}4x^4-4x^3+2x^2\right)\bigg|_{x=0}^{x=1} \\\\ = \boxed{\frac{13}{240}}](https://tex.z-dn.net/?f=%5Cdisplaystyle%5Cfrac14%5Cint_0%5E1x%281-x%29%5E2%282-x%29%5E2%5C%2C%5Cmathrm%20dx%20%3D%20%5Cleft%28%5Cfrac16x%5E6-%5Cfrac65x%5E5%2B%5Cfrac%7B13%7D4x%5E4-4x%5E3%2B2x%5E2%5Cright%29%5Cbigg%7C_%7Bx%3D0%7D%5E%7Bx%3D1%7D%20%5C%5C%5C%5C%20%3D%20%5Cboxed%7B%5Cfrac%7B13%7D%7B240%7D%7D)
<span>what are you asking?...............</span>
3300-20%=2640
$2640 is the answer to your question,hope this helps!please award brainliest??