The question is incomplete. The complete question is :
The breaking strengths of cables produced by a certain manufacturer have a mean of 1900 pounds, and a standard deviation of 65 pounds. It is claimed that an improvement in the manufacturing process has increased the mean breaking strength. To evaluate this claim, 150 newly manufactured cables are randomly chosen and tested, and their mean breaking strength is found to be 1902 pounds. Assume that the population is normally distributed. Can we support, at the 0.01 level of significance, the claim that the mean breaking strength has increased?
Solution :
Given data :
Mean, μ = 1900
Standard deviation, σ = 65
Sample size, n = 150
Sample mean, [tex]$\overline x$[/tex] = 1902
Level of significance = 0.01
The hypothesis are :
[tex]$H_0 : \mu = 1900$[/tex]
[tex]$H_1 : \mu > 1900$[/tex]
Test statics :
We use the z test as the sample size is large and we know the population standard deviation.
[tex]$z=\frac{\overline x - \mu}{\sigma / \sqrt{n}}$[/tex]
[tex]$z=\frac{1902-1900}{65 / \sqrt{150}}$[/tex]
[tex]$z=\frac{2}{5.30723}$[/tex]
[tex]$z=0.38$[/tex]
Finding the p-value:
P-value = P(Z > z)
= P(Z > 0.38)
= 1 - P(Z < 0.38)
From the z table. we get
P(Z < 0.38) = 0.6480
Therefore,
P-value = 1 - P(Z < 0.38)
= 1 - 0.6480
= 0.3520
Decision :
If the p value is less than 0.01, then we reject the [tex]H_0[/tex], otherwise we fail to reject [tex]H_0[/tex].
Since the value of p = 0.3520 > 0.01, the level of significance, then we fail to reject [tex]H_0[/tex].
Conclusion :
At a significance level of 0.01, we have no sufficient evidence to support that the mean breaking strength has increased.
g A gift shop sells 40 wind chimes per month at $110 each. The owners estimate that for each $11 increase in price, they will sell 2 fewer wind chimes per month. Find the price per wind chime that will maximize revenue.
Answer:
The price that maximizes the revenue is $165
Step-by-step explanation:
We can model the price as a function of sold units as a linear relationship.
Remember that a linear relationship is something like:
y = a*x + b
where a is the slope and b is the y-intercept.
We know that if the line passes through the points (x₁, y₁) and (x₂, y₂), then the slope can be written as:
a = (y₂ - y₁)/(x₂ - x₁)
For this line, we have the point (40, $110)
which means that to sell 40 units, the price must be $110
And we know that if the price increases by $11, then he will sell 2 units less.
Then we also have the point (38, $121)
So we know that our line passes through the points (40, $110) and (38, $121)
Then the slope of the line is:
a = ($121 - $110)/(38 - 40) = $11/-2 = -$5.5
Then the equation of the line is:
p(x) = -$5.5*x + b
to find the value of b, we can use the point (40, $110)
This means that when x = 40, the price is $110
then:
p(40) = $110 = -$5.5*40 + b
$110 = -$220 + b
$110 + $220 = b
$330 = b
Then the price equation is:
p(x) = -$5.5*x + $330
Now we want to find the maximum revenue.
The revenue for selling x items, each at the price p(x), is:
revenue = x*p(x)
replacing the p(x) by the equation we get:
revenue = x*(-$5.5*x + $330)
revenue = -$5.5*x^2 + $330*x
Now we want to find the x-value for the maximum revenue.
You can see that the revenue equation is a quadratic equation with a negative leading coefficient. This means that the maximum is at the vertex.
And remember that for a quadratic equation like:
y = a*x^2 + b*x + c
the x-value of the vertex is:
x = -b/2a
Then for our equation:
revenue = -$5.5*x^2 + $330*x
the x-vale of the vertex will be:
x = -$330/(2*-$5.5) = 30
x = 30
This means that the revenue is maximized when we sell 30 units.
And the price is p(x) evaluated in x = 30
p(30) = -$5.5*30 + $330 = $165
The price that maximizes the revenue is $165
Which equation represents a circle whose center is left parenthesis negative 7 comma 4 right parenthesis with a radius of 5?
Answer:
last option
Step-by-step explanation:
(x-h)²+(y-k)²=r²
(x--7)²+(y-4)²=5²
(x+7)²+(y-4)²=25
The equation of the circle is (x + 7)² + (y - 4)² = 25.
Option D is the correct answer.
What is a circle?A circle is a two-dimensional figure with a radius and circumference of 2pir.
The area of a circle is πr².
We have,
The equation of a circle with center (h,k) and radius r.
(x - h)² + (y - k)² = r²
Substituting the given values, we get:
(x - (-7))² + (y - 4)² = 5²
Simplifying the equation:
(x + 7)² + (y - 4)² = 25
Therefore,
The equation of the circle is (x + 7)² + (y - 4)² = 25
Learn more about Circle here:
https://brainly.com/question/11833983
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The length of a rectangle is 10 yd less than three times the width, and the area of the rectangle is 77 yd^2. Find the dimensions of the rectangle.
Answer:
W=7 and L=11
Step-by-step explanation:
We have two unknowns so we must create two equations.
First the problem states that length of a rectangle is 10 yd less than three times the width so: L= 3w-10
Next we are given the area so: L X W = 77
Then solve for the variable algebraically. It is just a system of equations.
3W^2 - 10W - 77 = 0
(3W + 11)(W - 7) = 0
W = -11/3 and/or W=7
Discard the negative solution as the width of the rectangle cannot be less then 0.
So W=7
Plug that into the first equation.
3(7)-10= 11 so L=11
Find the area of a triangle with the given description. (Round your answer to one decimal place.)
a triangle with sides of length 14 and 28 and included angle 20°
9514 1404 393
Answer:
67.0 square units
Step-by-step explanation:
The formula for the area is ...
Area = 1/2ab·sin(C)
Area = (1/2)(14)(28)sin(20°) ≈ 67.036 . . . . square units
The area of the triangle is about 67.0 square units.
find the value of the trigonometric ratio
Answer:
15/17
Step-by-step explanation:
sinA = CB/CA =15/17
Answer:
15/17Step-by-step explanation:
sine = opposite / hypotenusesin A = BC/ACsin A = 15/17use induction method to prove that 1.2^2+2.3^2+3.4^2+...+r(r+1)^2= n(n+1)(3n^2+11n+10)/12
Base case (n = 1):
• left side = 1×2² = 4
• right side = 1×(1 + 1)×(3×1² + 11×1 + 10)/12 = 4
Induction hypothesis: Assume equality holds for n = k, so that
1×2² + 2×3² + 3×4² + … + k × (k + 1)² = k × (k + 1) × (3k ² + 11k + 10)/12
Induction step (n = k + 1):
1×2² + 2×3² + 3×4² + … + k × (k + 1)² + (k + 1) × (k + 2)²
= k × (k + 1) × (3k ² + 11k + 10)/12 + (k + 1) × (k + 2)²
= (k + 1)/12 × (k × (3k ² + 11k + 10) + 12 × (k + 2)²)
= (k + 1)/12 × ((3k ³ + 11k ² + 10k) + 12 × (k ² + 4k + 4))
= (k + 1)/12 × (3k ³ + 23k ² + 58k + 48)
= (k + 1)/12 × (3k ³ + 23k ² + 58k + 48)
On the right side, we want to end up with
(k + 1) × (k + 2) × (3 (k + 1) ² + 11 (k + 1) + 10)/12
which suggests that k + 2 should be factor of the cubic. Indeed, we have
3k ³ + 23k ² + 58k + 48 = (k + 2) (3k ² + 17k + 24)
and we can rewrite the remaining quadratic as
3k ² + 17k + 24 = 3 (k + 1)² + 11 (k + 1) + 10
so we would arrive at the desired conclusion.
To see how the above rewriting is possible, we want to find coefficients a, b, and c such that
3k ² + 17k + 24 = a (k + 1)² + b (k + 1) + c
Expand the right side and collect like powers of k :
3k ² + 17k + 24 = ak ² + (2a + b) k + a + b + c
==> a = 3 and 2a + b = 17 and a + b + c = 24
==> a = 3, b = 11, c = 10
Which function is best represented by the graph in the image?
Answer:
No image I cannot tell you
Step-by-step explanation:
Please help on my hw
Answer:
b. The solution is a non empty set.
Step-by-step explanation:
There are no common elements.
a) Everyone on the team talks until the entire team agrees on one decision. O b) Everyone on the team discusses options and then votes. O c) The team passes the decision-making responsibility to an outside person. O di The team leader makes a decision without input from the other members.
Answer:
a) Everyone on the team talks until the entire team agrees on one decision.
Step-by-step explanation:
Option B consists of voting and not everyone would like the outcome. Option C is making an outsider the decision maker, which can't be helpful since he / she won't have as strong opinions as the team itself. Option D is just plain wrong as it defeats the purpose of team work and deciding as one team. So, I believe option A makes the most sense
The time it takes me to wash the dishes is uniformly distributed between 8 minutes and 17 minutes.
What is the probability that washing dishes tonight will take me between 14 and 16 minutes?
Give your answer accurate to two decimal places.
The time it takes to wash has the probability density function,
[tex]P(X=x) = \begin{cases}\frac1{17-8}=\frac19&\text{for }8\le x\le 17\\0&\text{otherewise}\end{cases}[/tex]
The probability that it takes between 14 and 16 minutes to wash the dishes is given by the integral,
[tex]\displaystyle\int_{14}^{16}P(X=x)\,\mathrm dx = \frac19\int_{14}^{16}\mathrm dx = \frac{16-14}9 = \frac29 \approx \boxed{0.22}[/tex]
If you're not familiar with calculus, the probability is equal to the area under the graph of P(X = x), which is a rectangle with height 1/9 and length 16 - 14 = 2, so the area and hence probability is 2/9 ≈ 0.22.
Determine whether each relation is a function. Give the domain and range for each relation.
{(3, 4), (3, 5), (4, 4), (4, 5)}
Answer:
Not a function
Domain: {3,4}
Range: {4,5}
Step-by-step explanation:
A function is a relation where each input has its own output. In other words if the x value has multiple corresponding y values then the relation is not a function
For the relation given {(3, 4), (3, 5), (4, 4), (4, 5)} the x value 3 and 4 have more than one corresponding y value therefore the relation shown is not a function
Now let's find the domain and range.
Domain is the set of x values in a relation.
The x values of the given relation are 3 and 4 so the domain is {3,4}
The range is the set of y values in a relation
The y value of the given relation include 4 and 5
So the range would be {4,5}
Notes:
The values of x and y should be written from least to greatest when writing them out as domain and range.
They should be written inside of brackets
Do not repeat numbers when writing the domain and range
Question 19 of 28
Which of the following equations can be used to find the length of BC in the
triangle below?
B
10
А
30
с
A. BC = 30 + 10
B. (BC)2 = 102 + 302
C. BC = 30 - 10
D. (BC)2 = 302 - 102
Answer:
BC^2=10^2+30^2
Step-by-step explanation:
P=10B=30Using pythagorean theorem
[tex]\\ \sf\longmapsto BC^2=10^2+30^2[/tex]
[tex]\\ \sf\longmapsto BC^2=100+300[/tex]
[tex]\\ \sf\longmapsto BC^2=400[/tex]
[tex]\\ \sf\longmapsto BC=\sqrt{400}[/tex]
[tex]\\ \sf\longmapsto BC=20[/tex]
Find the diameter of a circle if the area is
153.86m2. Use 3.14 for pi.
Answer:
-Hello Fatema!
The formula to find out the area of a circle is πd so let's plug the known values and then solve for d [ diameter ] :[tex] \boxed{ \large{ \tt{✺ \: AREA \: OF \: A \: CIRCLE = \pi \: d }}}[/tex]
[tex] \large{ \tt{⟶ \: 153.86 = 3.14 \: d}}[/tex]
[tex] \large{ \tt{⟶ \: d = \frac{153.86}{3.14} }}[/tex]
[tex] \large{ \tt{⟶d = 49 \: m}}[/tex]
[tex] \large{ \boxed{ \boxed{ \tt{⤿ \: OUR \: FINAL \: ANSWER : \: 49 \: m}}}}[/tex]
Yayy! We're done! Let me know if you have any questions regarding my answer and also , notify me if you need any other help! :)I will give you brainliest if you answer this correctly
Answer:
Mark Brainliest please
The answer is 1
Step-by-step explanation:
(1 — x^ m-n) ^-1 + (1- x ^n-m)^ -1
1/[1-x^(m-n)] + 1/[1-x^(n-m)]
1/[1-x^m × x^(-n)] + 1/[1-x^n × x^(-m)]
x^n/(x^n - x^m) + x^m/(x^m - x^n)
x^n/(x^n - x^m) - x^m/(x^n - x^m)
Now taking the LCM here, we get
(x^n - x^m)/(x^n - x^m)
Working at home: According to the U.S Census Bureau, 41% of men who worked at home were college graduates. In a sample of 506 women who worked at home, 166 were college graduates. Part: 0 / 30 of 3 Parts Complete Part 1 of 3 (a) Find a point estimate for the proportion of college graduates among women who work at home. Round the answer to at least three decimal places. The point estimate for the proportion of college graduates among women who work at home is .
Solution :
a). The point estimate of proportion of college graduates among women who work at home,
[tex]$\hat p =\frac{166}{506}$[/tex]
= 0.3281
99.5% confidence interval
[tex]$=\left( \hat p \pm Z_{0.005/2} \sqrt{\frac{\hat p (1- \hat p)}{n}} \right)$[/tex]
[tex]$=\left( 0.3281 \pm 2.81 \sqrt{\frac{0.3281 \times (1- 0.3281)}{506}} \right)$[/tex]
[tex]$=(0.3281 \pm 0.0586)$[/tex]
[tex]$=(0.2695, 0.3867)$[/tex]
HURRY plSSSSSSSSSSSSSSSSSSSSSS
What is the measure of the unknown angle?
Image of a straight angle divided into two angles. One angle is eighty degrees and the other is unknown.
Answer:
The unknown is 100
Step-by-step explanation:
A straight line is 180 degrees
We have two angles x, and 80
x+80 = 180
x = 180-80
x= 100
How many centilitres are in 156000m^3
9514 1404 393
Answer:
1.56×10^10 cL
Step-by-step explanation:
There are 1000 liters in a cubic meter, so 10^5 centiliters in a cubic meter. The 1.56×10^5 cubic meters will then have ...
(1.56×10^5 m^3)×(10^5 cL/m^3) = 1.56×10^10 cL
_____
That's 15,600,000,000 cL.
"Centi-" is a prefix meaning 1/100.
On Halloween, a man presents a child with a bowl containing eight different pieces of candy. He tells her that she may have three pieces. How many choices does she have
Answer:
[tex]56[/tex] choices
Step-by-step explanation:
We know that we'll have to solve this problem with a permutation or a combination, but which one do we use? The answer is a combination because the order in which the child picks the candy does not matter.
To further demonstrate this, imagine I have 4 pieces of candy labeled A, B, C, and D. I could choose A, then C, then B or I could choose C, then B, then A, but in the end, I still have the same pieces, regardless of what order I pick them in. I hope that helps to understand why this problem will be solved with a combination.
Anyways, back to the solving! Remember that the combination formula is
[tex]_nC_r=\frac{n!}{r!(n-r)!}[/tex], where n is the number of objects in the sample (the number of objects you choose from) and r is the number of objects that are to be chosen.
In this case, [tex]n=8[/tex] and [tex]r=3[/tex]. Substituting these values into the formula gives us:
[tex]_8C_3=\frac{8!}{3!5!}[/tex]
[tex]= \frac{8*7*6*5*4*3*2*1}{3*2*1*5*4*3*2*1}[/tex] (Expand the factorials)
[tex]=\frac{8*7*6}{3*2*1}[/tex] (Cancel out [tex]5*4*3*2*1[/tex])
[tex]=\frac{8*7*6}{6}[/tex] (Evaluate denominator)
[tex]=8*7[/tex] (Cancel out [tex]6[/tex])
[tex]=56[/tex]
Therefore, the child has [tex]\bf56[/tex] different ways to pick the candies. Hope this helps!
An electrician charges a fee of $40 plus $25 per hour. Let y be the cost in dollars of using the electrician for x hours. Choose the correct equation.
y = 40x - 25
y = 25x + 40
y = 25x - 40
y = 40x + 25
Answer:
y = 25x + 40
Step-by-step explanation:
The electrician charges $25 per hour.
The number of hours is x.
Therefore after x hours the electrician will charge $25x. (multiply the charge by the number of hours $25 * x)
Therefore fee(y) charged by the electrician = $40 + $25x
Hence y = 25x + 40
Write the equation of the line that passes through the points (- 5, 1) and (2, 0) . Put your answer in fully reduced slope intercept form, unless it is a vertical or horizontal line
Pls help me with this one:(
Answer:
y=-1/7x + 12/7
Step-by-step explanation:
Start by finding the slope
m=(1-0)/(-5-2)
m=-1/7
next plug the slope and the point (-5,1) into point slope formula
y-y1=m(x-x1)
y1=1
x1= -5
m=-1/7
y- 1 = -1/7(x - -5)
y-1=-1/7(x+5)
Distribute -1/7 first
y- 1=-1/7x + 5/7
Add 1 on both sides, but since its a fraction add 7/7
y=-1/7x + (5/7+7/7)
y=-1/7x+12/7
Answer:
Step-by-step explanation:
(-5,1) (2,0)
m=(y-y)/(x-x)
m = (0-1)/2- -5)
m = -1/7
(2,0)
y-0= -1/7 (x-2)
y = -1/7x + 2/7
If (4x-5) :(9x-5) = 3:8 find the value of x.
Answer:
x is 5
Step-by-step explanation:
[tex] \frac{4x - 5}{9x - 5} = \frac{3}{8} \\ \\ 8(4x - 5) = 3(9x - 5) \\ 32x - 40 = 27x - 15 \\ 5x = 25 \\ x = \frac{25}{5} \\ \\ x = 5[/tex]
Step-by-step explanation:
as you can see as i solved above. all you need to do was to rationalize the both equations
14. A quadratic equation is graphed above.
Which of the following equations could be
paired with the graphed equation to create
a system of equations whose solution set is
comprised of the points (2,-2) and (-3, 3)?
A. y = x + 6
B. y = x - 6
C. y = X
D. y = -x
Answer:
D.
Step-by-step explanation:
2=-2，3=-3
2²=-2²，3²=3²
4) The measure of the linear density at a point of a rod varies directly as the third power of the measure of the distance of the point from one end. The length of the rod is 4 ft and the linear density is 2 slugs/ft at the center, find the total mass of the given rod and the center of the mass
Answer:
a. 16 slug b. 3.2 ft
Step-by-step explanation:
a. Total mass of the rod
Since the linear density at a point of the rod,λ varies directly as the third power of the measure of the distance of the point form the end, x
So, λ ∝ x³
λ = kx³
Since the linear density λ = 2 slug/ft at then center when x = L/2 where L is the length of the rod,
k = λ/x³ = λ/(L/2)³ = 8λ/L³
substituting the values of the variables into the equation, we have
k = 8λ/L³
k = 8 × 2/4³
k = 16/64
k = 1/4
So, λ = kx³ = x³/4
The mass of a small length element of the rod dx is dm = λdx
So, to find the total mass of the rod M = ∫dm = ∫λdx we integrate from x = 0 to x = L = 4 ft
M = ∫₀⁴dm
= ∫₀⁴λdx
= ∫₀⁴(x³/4)dx
= (1/4)∫₀⁴x³dx
= (1/4)[x⁴/4]₀⁴
= (1/16)[4⁴ - 0⁴]
= (256 - 0)/16
= 256/16
= 16 slug
b. The center of mass of the rod
Let x be the distance of the small mass element dm = λdx from the end of the rod. The moment of this mass element about the end of the rod is xdm = λxdx = (x³/4)xdx = (x⁴/4)dx.
We integrate this through the length of the rod. That is from x = 0 to x = L = 4 ft
The center of mass of the rod x' = ∫₀⁴(x⁴/4)dx/M where M = mass of rod
= (1/4)∫₀⁴x⁴dx/M
= (1/4)[x⁵/5]₀⁴/M
= (1/20)[x⁵]₀⁴/M
= (1/20)[4⁵ - 0⁵]/M
= (1/20)[1024 - 0]/M
= (1/20)[1024]/M
Since M = 16, we have
x' = (1/20)[1024]/16
x' = 64/20
x' = 3.2 ft
If 5000 is divided by 10 and 10 again what answer will be reached
Hey there!
First, divide 5,000 by 10. You will get 500.
Now, 500 ÷ 10, and you will get your answer, 50.
Hope this helps! Have a great day!
Solve the system of equations.
6x−y=−14
2x−3y=6
whats the answer please C:
Answer:
Step-by-step explanation:
Subsets and Sets HELP
Attached is the photo reference
Answer:
(a) (C U D) = {k, m, y, z}
(b) C ∩ D = {z}
Hannah's suitcase has the following dimensions.
length: 27 inches
width: 21 inches
depth: 14 inches
What is the volume of Hannah's suitcase in cubic inches?
Answer:7938 inches square
Step-by-step explanation:
multiply everything
Answer:
7938
Step-by-step explanation:
please help!!!!!!!!!!
9514 1404 393
Answer:
-203.1875
Step-by-step explanation:
The ends of the interval are ...
(-4, g(-4)) = (-4, 1023 15/16)
(1, g(1)) = (1, 8)
The average rate of change is the slope of the line between these two points:
m = (y2 -y1)/(x2 -x1)
m = (8 -(1023 15/16))/(1 -(-4)) = (-1015 15/16)/5 = -203 3/16
The average rate of change on the interval is -203 3/16.
f(x)=2^x. show that f(x=3)=8 f(x)?
Step-by-step explanation:
[tex]f(x) = {2}^{x} [/tex]
x = 3
f(3) = 2³ = 2×2×2 = 4×2 = 8
Look at images below. : ]
Answer:
1) A
B) 5.818 stops
Step-by-step explanation:
Number One is less than or equal to 21 because the person only has 21 dollars, so she can't spend more than 21.
B can be solved through the equation by first subtracting $5, and then dividing 2.75 by 16.
