Answer:
We conclude that the mean is greater than 25.
Step-by-step explanation:
We are given the following in the question:
Population mean, μ = 25
Sample mean,
= 27
Sample size, n = 100
Alpha, α = 0.05
Sample standard deviation, s = 6.5
First, we design the null and the alternate hypothesis
![H_{0}: \mu = 25\\H_A: \mu> 25](https://tex.z-dn.net/?f=H_%7B0%7D%3A%20%5Cmu%20%3D%2025%5C%5CH_A%3A%20%5Cmu%3E%2025)
We use One-tailed(right) z test to perform this hypothesis.
Formula:
![z_{stat} = \displaystyle\frac{\bar{x} - \mu}{\frac{s}{\sqrt{n}} }](https://tex.z-dn.net/?f=z_%7Bstat%7D%20%3D%20%5Cdisplaystyle%5Cfrac%7B%5Cbar%7Bx%7D%20-%20%5Cmu%7D%7B%5Cfrac%7Bs%7D%7B%5Csqrt%7Bn%7D%7D%20%7D)
Putting all the values, we have
![z_{stat} = \displaystyle\frac{27 - 25}{\frac{6.5}{\sqrt{100}} } = 3.07](https://tex.z-dn.net/?f=z_%7Bstat%7D%20%3D%20%5Cdisplaystyle%5Cfrac%7B27%20-%2025%7D%7B%5Cfrac%7B6.5%7D%7B%5Csqrt%7B100%7D%7D%20%7D%20%3D%203.07)
Now, ![z_{critical} \text{ at 0.05 level of significance } = 1.645](https://tex.z-dn.net/?f=z_%7Bcritical%7D%20%5Ctext%7B%20at%200.05%20level%20of%20significance%20%7D%20%3D%201.645)
Since,
![z_{stat} > z_{critical}](https://tex.z-dn.net/?f=z_%7Bstat%7D%20%3E%20z_%7Bcritical%7D)
We reject the null hypothesis and accept the alternate hypothesis.
Thus, the mean is greater than 25.
Let
be the amount of the 30% alloy and
the amount of the 60% alloy the metalworker will use. However much is used, the final alloy will have a mass of
![x+y=100](https://tex.z-dn.net/?f=x%2By%3D100)
kilograms. For each kg of the 30% alloy used, 0.3 kg is copper; similary, each kg of the 60% alloy contributes 0.6 kg, so that
![0.3x+0.6y=0.54(x+y)=54](https://tex.z-dn.net/?f=0.3x%2B0.6y%3D0.54%28x%2By%29%3D54)
Now,
![x+y=100\implies y=100-x](https://tex.z-dn.net/?f=x%2By%3D100%5Cimplies%20y%3D100-x)
![\implies0.3x+0.6(100-x)=54](https://tex.z-dn.net/?f=%5Cimplies0.3x%2B0.6%28100-x%29%3D54)
![\implies60-0.3x=54](https://tex.z-dn.net/?f=%5Cimplies60-0.3x%3D54)
![\implies0.3x=6](https://tex.z-dn.net/?f=%5Cimplies0.3x%3D6)
![\implies x=20](https://tex.z-dn.net/?f=%5Cimplies%20x%3D20)
![\implies y=100-20=80](https://tex.z-dn.net/?f=%5Cimplies%20y%3D100-20%3D80)
6.
![1 \frac{1}{2} = \frac{6}{4}](https://tex.z-dn.net/?f=1%20%5Cfrac%7B1%7D%7B2%7D%20%3D%20%5Cfrac%7B6%7D%7B4%7D%20)
since
![\frac{1}{4} = 4](https://tex.z-dn.net/?f=%20%5Cfrac%7B1%7D%7B4%7D%20%3D%204%20)
feet. Then 6*4=24 So the answer is C
7. 1200 m/8 cm = C. 1 cm = 150 m
8. A. Since 1 in = 3 feet then 6 inches = 18 feet (6*3=18) and 4 inches = 12 feet (4*3=12) so the dimensions of her room are 16'x12'.
B. A=lxw so 16*12= 216
![m^{2}](https://tex.z-dn.net/?f=%20%20m%5E%7B2%7D%20)
Hope that helps
Answer:
48π in³
Step-by-step explanation:
![V=\frac{1}{3} \pi r^2h](https://tex.z-dn.net/?f=V%3D%5Cfrac%7B1%7D%7B3%7D%20%5Cpi%20r%5E2h)
Plug in the radius 6 in and the height 4 in
![V=\frac{1}{3} \pi (6)^2(4)\\V=\frac{1}{3} \pi (36)(4)\\V=\frac{1}{3} \pi (144)\\V=48\pi](https://tex.z-dn.net/?f=V%3D%5Cfrac%7B1%7D%7B3%7D%20%5Cpi%20%286%29%5E2%284%29%5C%5CV%3D%5Cfrac%7B1%7D%7B3%7D%20%5Cpi%20%2836%29%284%29%5C%5CV%3D%5Cfrac%7B1%7D%7B3%7D%20%5Cpi%20%28144%29%5C%5CV%3D48%5Cpi)
Therefore, the volume of the cone is 48π in³.
I hope this helps!
Option C:
The coefficient of
is 40.
Solution:
Given expression:
![(2 x+y)^{5}](https://tex.z-dn.net/?f=%282%20x%2By%29%5E%7B5%7D)
Using binomial theorem:
![(a+b)^{n}=\sum_{i=0}^{n}\left(\begin{array}{l}n \\i\end{array}\right) a^{(n-i)} b^{i}](https://tex.z-dn.net/?f=%28a%2Bb%29%5E%7Bn%7D%3D%5Csum_%7Bi%3D0%7D%5E%7Bn%7D%5Cleft%28%5Cbegin%7Barray%7D%7Bl%7Dn%20%5C%5Ci%5Cend%7Barray%7D%5Cright%29%20a%5E%7B%28n-i%29%7D%20b%5E%7Bi%7D)
Here ![a=2 x, b=y](https://tex.z-dn.net/?f=a%3D2%20x%2C%20b%3Dy)
Substitute in the binomial formula, we get
![(2x+y)^5=\sum_{i=0}^{5}\left(\begin{array}{l}5 \\i\end{array}\right)(2 x)^{(5-i)} y^{i}](https://tex.z-dn.net/?f=%282x%2By%29%5E5%3D%5Csum_%7Bi%3D0%7D%5E%7B5%7D%5Cleft%28%5Cbegin%7Barray%7D%7Bl%7D5%20%5C%5Ci%5Cend%7Barray%7D%5Cright%29%282%20x%29%5E%7B%285-i%29%7D%20y%5E%7Bi%7D)
Now to expand the summation, substitute i = 0, 1, 2, 3, 4 and 5.
![$=\frac{5 !}{0 !(5-0) !}(2 x)^{5} y^{0}+\frac{5 !}{1 !(5-1) !}(2 x)^{4} y^{1}+\frac{5 !}{2 !(5-2) !}(2 x)^{3} y^{2}+\frac{5 !}{3 !(5-3) !}(2 x)^{2} y^{3}](https://tex.z-dn.net/?f=%24%3D%5Cfrac%7B5%20%21%7D%7B0%20%21%285-0%29%20%21%7D%282%20x%29%5E%7B5%7D%20y%5E%7B0%7D%2B%5Cfrac%7B5%20%21%7D%7B1%20%21%285-1%29%20%21%7D%282%20x%29%5E%7B4%7D%20y%5E%7B1%7D%2B%5Cfrac%7B5%20%21%7D%7B2%20%21%285-2%29%20%21%7D%282%20x%29%5E%7B3%7D%20y%5E%7B2%7D%2B%5Cfrac%7B5%20%21%7D%7B3%20%21%285-3%29%20%21%7D%282%20x%29%5E%7B2%7D%20y%5E%7B3%7D)
![$+\frac{5 !}{4 !(5-4) !}(2 x)^{1} y^{4}+\frac{5 !}{5 !(5-5) !}(2 x)^{0} y^{5}](https://tex.z-dn.net/?f=%24%2B%5Cfrac%7B5%20%21%7D%7B4%20%21%285-4%29%20%21%7D%282%20x%29%5E%7B1%7D%20y%5E%7B4%7D%2B%5Cfrac%7B5%20%21%7D%7B5%20%21%285-5%29%20%21%7D%282%20x%29%5E%7B0%7D%20y%5E%7B5%7D)
Let us solve the term one by one.
![$\frac{5 !}{0 !(5-0) !}(2 x)^{5} y^{0}=32 x^{5}](https://tex.z-dn.net/?f=%24%5Cfrac%7B5%20%21%7D%7B0%20%21%285-0%29%20%21%7D%282%20x%29%5E%7B5%7D%20y%5E%7B0%7D%3D32%20x%5E%7B5%7D)
![$\frac{5 !}{1 !(5-1) !}(2 x)^{4} y^{1} = 80 x^{4} y](https://tex.z-dn.net/?f=%24%5Cfrac%7B5%20%21%7D%7B1%20%21%285-1%29%20%21%7D%282%20x%29%5E%7B4%7D%20y%5E%7B1%7D%20%3D%2080%20x%5E%7B4%7D%20y)
![$\frac{5 !}{2 !(5-2) !}(2 x)^{3} y^{2}= 80 x^{3} y^{2}](https://tex.z-dn.net/?f=%24%5Cfrac%7B5%20%21%7D%7B2%20%21%285-2%29%20%21%7D%282%20x%29%5E%7B3%7D%20y%5E%7B2%7D%3D%2080%20x%5E%7B3%7D%20y%5E%7B2%7D)
![$\frac{5 !}{3 !(5-3) !}(2 x)^{2} y^{3}= 40 x^{2} y^{3}](https://tex.z-dn.net/?f=%24%5Cfrac%7B5%20%21%7D%7B3%20%21%285-3%29%20%21%7D%282%20x%29%5E%7B2%7D%20y%5E%7B3%7D%3D%2040%20x%5E%7B2%7D%20y%5E%7B3%7D)
![$\frac{5 !}{4 !(5-4) !}(2 x)^{1} y^{4}= 10 x y^{4}](https://tex.z-dn.net/?f=%24%5Cfrac%7B5%20%21%7D%7B4%20%21%285-4%29%20%21%7D%282%20x%29%5E%7B1%7D%20y%5E%7B4%7D%3D%2010%20x%20y%5E%7B4%7D)
![$\frac{5 !}{5 !(5-5) !}(2 x)^{0} y^{5}=y^{5}](https://tex.z-dn.net/?f=%24%5Cfrac%7B5%20%21%7D%7B5%20%21%285-5%29%20%21%7D%282%20x%29%5E%7B0%7D%20y%5E%7B5%7D%3Dy%5E%7B5%7D)
Substitute these into the above expansion.
![(2x+y)^5=32 x^{5}+80 x^{4} y+80 x^{3} y^{2}+40 x^{2} y^{3}+10 x y^{4}+y^{5}](https://tex.z-dn.net/?f=%282x%2By%29%5E5%3D32%20x%5E%7B5%7D%2B80%20x%5E%7B4%7D%20y%2B80%20x%5E%7B3%7D%20y%5E%7B2%7D%2B40%20x%5E%7B2%7D%20y%5E%7B3%7D%2B10%20x%20y%5E%7B4%7D%2By%5E%7B5%7D)
The coefficient of
is 40.
Option C is the correct answer.