Answer:
Step-by-step explanation:
the first and last choices look good
How to do this question?
Answer:
40
Step-by-step explanation:
2x² - 5y + 7 when x = 2 and y = -5
2(2)² - 5(-5) + 7
= 2(4) -5(-5) + 7
= 8 + 25 + 7
= 40
Suppose you choose a marble from a bag containing 4 red marbles, 2 white marbles, and 3 blue marbles. You return the first marble to the bag and then choose again. Find P(red then blue).
Answer:
4/27
Step-by-step explanation:
total number of marbles=9
probability of red=4/9
since you returned the first marble, the total number of marbles remains the same
prob(Blue)=(3/9)=1/3
P(red then blue)=(4/9)*(1/3)
=4/27
A piece of wire 11 m long is cut into two pieces. One piece is bent into a square and the other is bent into an equilateral triangle. (a) How much wire should be used for the square in order to maximize the total area
Answer:
11 meters
Step-by-step explanation:
First, we can say that the square has a side length of x. The perimeter of the square is 4x, and that is how much wire goes into the square. To maximize the area, we should use all the wire possible, so the remaining wire goes into the triangle, or (11-4x).
The area of the square is x², and the area of an equilateral triangle with side length a is (√3/4)a². Next, 11-4x is equal to the perimeter of the triangle, and since it is equilateral, each side has (11-4x)/3 length. Plugging that in for a, we get the area of the equilateral triangle is
(√3/4)((11-4x)/3)²
= (√3/4)(11/3 - 4x/3)²
= (√3/4)(121/9 - 88x/9 + 16x²/9)
= (16√3/36)x² - (88√3/36)x + (121√3/36)
The total area is then
(16√3/36)x² - (88√3/36)x + (121√3/36) + x²
= (16√3/36 + 1)x² - (88√3/36)x + (121√3/36)
Because the coefficient for x² is positive, the parabola would open up and the derivative of the parabola would be the local minimum. Therefore, to find the maximum area, we need to go to the absolute minimum/maximum points of x (x=0 or x=2.75)
When x=0, each side of the triangle is 11/3 meters long and its area is
(√3/4)a² ≈ 5.82
When x=2.75, each side of the square is 2.75 meters long and its area is
2.75² = 7.5625
Therefore, a maximum is reached when x=2.75, or the wire used for the square is 2.75 * 4 = 11 meters
The length of the square must be 4 m in order to maximize the total area.
What are the maxima and minima of a function?When we put the differentiation of the given function as zero and find the value of the variable we get maxima and minima.
We have,
Length of the wire = 11 m
Let the length of the wire bent into a square = x.
The length of the wire bent into an equilateral triangle = (11 - x)
Now,
The perimeter of a square = 4 side
4 side = x
side = x/4
The perimeter of an equilateral triangle = 3 side
11 - x = 3 side
side = (11 - x)/3
Area of square = side²
Area of equilateral triangle = (√3/4) side²
Total area:
T = (x/4)² + √3/4 {(11 -x)/3}² _____(1)
Now,
To find the maximum we will differentiate (1)
dT/dx = 0
2x/4 + (√3/4) x 2(11 - x)/3 x -1 = 0
2x / 4 - (√3/4) x 2(11 - x)/3 = 0
2x/4 - (√3/6)(11 - x) = 0
2x / 4 = (√3/6)(11 - x)
√3x = 11 - x
√3x + x = 11
x (√3 + 1) = 11
x = 11 / (1.732 + 1)
x = 11/2.732
x = 4
Thus,
The length of the square must be 4 m in order to maximize the total area.
Learn more about maxima and minima here:
https://brainly.com/question/13178975
#SPJ5
For a certain country, the bar graph shows the population of it’s public school students, in millions, and the amount that the country’s government spent on public education, in billions of dollars, for five selected years. Complete part A and B.
A.
Express 2007 student population in scientific notation. (Use the multiplication symbol as needed)
B.
Express the amount that the government spent on public education in 2007 in scientific notation. (Use the multiplication symbol as needed)
Answer:
B
Step-by-step explanation:
I took a test in school and this was the answer...at least for my class.
Carmen Martinez
What is the slope of the line that passes through the point 4,4 and 10,7 write your answer in simplest form
[tex]\boxed{\sf Slope(m)=\dfrac{y_2-y_1}{x_2-x_1}}[/tex]
[tex]\\ \sf\longmapsto m=\dfrac{7-4}{10-4}[/tex]
[tex]\\ \sf\longmapsto m=\dfrac{3}{6}[/tex]
[tex]\\ \sf\longmapsto m=\dfrac{1}{2}[/tex]
[tex]\\ \sf\longmapsto m\approx0.5[/tex]
Answer:
[tex]m=\frac{1}{2}[/tex]
Step-by-step explanation:
The slope of a line, also known as the change in the line or the ([tex]\frac{rise}{run}[/tex]) can be found using the following formula,
[tex]m=\frac{y_2-y_1}{x_2-x_1}[/tex]
Where ([tex]x_1,y_1[/tex]) and ([tex]x_2,y_2[/tex]) are points on the line. Substitute the given information into the formula and solve for the slope.
[tex]m=\frac{y_2-y_1}{x_2-x_1}[/tex]
Points on the line: [tex](4,4)\ \ \ (10, 7)[/tex]
[tex]m=\frac{y_2-y_1}{x_2-x_1}[/tex]
[tex]m=\frac{7-4}{10-4}[/tex]
[tex]m=\frac{3}{6}[/tex]
[tex]m=\frac{1}{2}[/tex]
[tex]m=0.5[/tex]
Based on corresponding angles and vertical angles, which angles must always be congruent to the angles given? Complete the table.
Answer:
A and B must always be congruent
B and D
E and G
F and H
Step-by-step explanation:
I have to be honest. from the picture I cannot see the vertical angles. All I see is a straight blue line and red letters. But based on the vertical theorem
A and B must always be congruent
B and D
E and G
F and H
also if you want to make sure it's right try to include another picture.
Answer:
Step-by-step explanation:
edmentum :)
A refrigerator magnet uses five eights of an inch of magnetic tape how many refrigerator magnets can you make with 10 inches of magnetic tape
ANSWER: You can make 16 refrigerator magnets.
If you divide 10 by 5/8, you multiply by the reciprocal of 5/8 which is 8/5. You have 8/5 x 10. Cross simplify and you have 16.
14 cm 8 cm 10cm 5 cm.
find the area and the perimeter of the above figures
Perimeter = Sum of all sides
Perimeter = 14cm + 8cm + 10cm + 5cm
Perimeter = 22cm + 15cm
Perimeter = 37cm
Step-by-step explanation:
hope it helps you
...
........
In the Data Analysis portion of the article the authors report that they completed a power analysis to determine the power of their study with the sample size utilized. They report a power of 90%. What does this mean
Answer:
Kindly check explanation
Step-by-step explanation:
The power of a test simply gives the probability of Rejecting the Null hypothesis, H0 in a statistical analysis given that the the alternative hypothesis, H1 for the study is true. Hence, the power of a test can be referred to as the probability of a true positive outcome in an experiment.
Using this definition, a power of 90% simply means that ; there is a 90% probability that the a Pvalue less Than the α - value of an experiment is obtained if there is truly a significant difference. Hence, a 90% chance of Rejecting the Null hypothesis if truly the alternative hypothesis is true.
look at the image below over 100000000 points brainly instructer
Answer:
~~314.16
Step-by-step explanation:
lol i dont have 100000000 points. anyways
you can find the area of a sphere with the formula 4πr^2 with r being the radius
this sphere's radius is 5 as shown in the image
so
4π*r^2
4π*(5)^2
=4π*25
=100π
put into calculator
~~314.16cm^3
hope this helps
the image is located at the bottom of the screen.
Answer:
..... surface area = 16 km^2.
Which of the following sets shows all the numbers from the set {0.5,1,2.5,3,3.5} that make the inequality 4a + 2 > 12 true
============================================================
Explanation:
Let's isolate the variable 'a' in the given inequality.
4a + 2 > 12
4a + 2-2 > 12-2
4a > 10
4a/4 > 10/4
a > 2.5
In the second step, I subtracted 2 from both sides to undo the "plus 2". In the second to last step, I divided both sides by 4 to undo the multiplication.
The solution is a > 2.5, meaning that anything larger than 2.5 will work in the original inequality.
For example, we could try a = 3 to get
4a + 2 > 12
4*3 + 2 > 12
12 + 2 > 12
14 > 12
which is true. This makes a = 3 a solution. The value a = 3.5 is a similar story, so it's also a solution.
------------
As an example of a non-solution, let's try a = 1
4a + 2 > 12
4*1 + 2 > 12
4 + 2 > 12
6 > 12
which is false. So we can see why a = 1 is not part of the solution set. You should find that a= 0.5 and a = 2.5 won't work as well for similar reasoning.
A car rental firm has 440 cars. Sixty-three of these cars have defective turn signals and 39 have defective tires. (Enter your probabilities as fractions.) (a) What is the probability that one of these cars selected at random does not have defective turn signals
Answer:
The probability is 0.857
Step-by-step explanation:
We know that:
There is a total of 440 cars
There are 63 cars with defective turn signals
There are 39 with defective tires.
Now we want to find the probability that a randomly selected car does not have defective turn signals.
If all the cars have the same probability of being selected, this probability will be equal to the quotient between the number of cars that do not have defective turn signals and the total number of cars.
We know that the total number of cars is 440
And 63 of these have defective turn signals, then the rest don't.
440 - 63 = 377 cars do not have defective turn signals.
Then the probability is:
P = 377/440 = 0.857
which of the following is equal to the square root of 27/16
Answer:
Step-by-step explanation:
Prime factorize 27 and 16
27 = 3 * 3 * 3
16 = 2 * 2 * 2 * 2
[tex]\frac{\sqrt{27}}{\sqrt{16}}=\frac{\sqrt{3*3*3}}{\sqrt{2*2*2*2}}[/tex]
[tex]= \frac{3\sqrt{3}}{2*2}\\\\\\=\frac{3\sqrt{3}}{4}[/tex]
Answer: (3√3)/4
Explanation:
√(27/16)
=(3√3)/4
Because 27 = 3²×3
And 16 = 4²
So 4 is left and one 3 goes out and one stays in
Please click thanks and mark brainliest if you like
Solve each equation.
1)-9 + x = 4
Instructions: Find the missing side. Round your answer to the
nearest tenth
Answer:
49
Step-by-step explanation:
sin(theta) = P/H
sin(28)=23/x, x=23/sin(28)=49
help me plzzzzzzzzzzzzzzzzzzzzzzzzzz
Intro to Translations
Acellus
Find the image of the given point
under the given translation.
P(-1,2)
T(x, y) = (x + 2, y - 4)
P' = ([?], [])
Enter the number that belongs
in the green box.
Answer:
(1,-2)
Step-by-step explanation:
P(-1,2) and (x, y) -> (x + 2, y - 4). Plugging in x and y in the transformation, the transformed points are (-1+2, 2-4) = (1,-2)
find the surface area of prism
Answer:
114 cm²
Step-by-step explanation:
Surface area of the rectangular prism,
2(wl+hl+hw)
=2×(3×8+3×8+3×3)
=2×(24+24+9)
=2×(57)
=114 cm²
compute (-12)+(-8)+30
[tex]\huge\text{Hey there!}[/tex]
[tex]\large\textsf{-12 + (-8) + 30}\\\\\large\textsf{= -12 - 8 + 30}\\\\\large\textsf{-12 - 8 = \bf -20}\\\\\large\textsf{= -20 + 30}\\\\\large\textsf{= \bf 10}\\\\\\\boxed{\boxed{\huge\text{Therefore, your ANSWER is: \textsf{10}}}}\huge\checkmark\\\\\\\\\huge\textsf{Good luck on your assignment \& enjoy your day!}[/tex]
~[tex]\frak{Amphitrite1040:)}[/tex]
Please help me!
14
33
46
60
200
Answer:
46
Step-by-step explanation:
200/2 = 100, and the x coordinate that line up with the y-coordinate of 100 is 46.
An airplane started at 0 feet. It rose 21,000 feet at takeoff. It then descended 4,329 feet because of clouds. An oncoming plane was approaching, so it rose 6,333 feet. After the oncoming plane passed, it descended 8,453 feet, at what altitude was the plane flying?
Can anyone please help me out?
Consider the differential equation: 2y′′−13y′−7y = 0
a. Show that, for any constants A and B, the following is a solution to the above differential equation: y = Ae^(−9x)+Be^(x/3)
b. Find the values A and B that make the above general solution into a solution for the following initial value problem: 2y′′−13y′−7y = 0; y(0) = 3, y′(0) = −5
--------------------------------------------------
Just a correction, the characteristic roots of the equation are [tex]y = 7[/tex] and [tex]y = -\frac{1}{2}[/tex], thus, we should test for:
[tex]y = Ae^{7x} + Be^{-\frac{x}{2}}[/tex]
--------------------------------------------------
Question a:
First, we find the derivatives, thus:[tex]y = Ae^{7x} + Be^{-\frac{x}{2}}[/tex]
[tex]y^{\prime} = 7Ae^{-7x} - \frac{1}{2}Be^{-\frac{x}{2}}[/tex]
[tex]y^{\prime\prime} = 49Ae^{-7x} + \frac{1}{4}Be^{-\frac{x}{2}}[/tex]
Now, we replace into the equation:[tex]2y^{\prime\prime} - 13y^{\prime} - 7y = 0[/tex]
[tex]2(49Ae^{-7x} + \frac{1}{4}Be^{-\frac{x}{2}}) - 13(7Ae^{-7x} - \frac{1}{2}Be^{-\frac{x}{2}}) - 7(Ae^{7x} + Be^{-\frac{x}{2}}) = 0[/tex]
[tex]98Ae^{-7x} + \frac{1}{2}Be^{\frac{x}{2}} - 91Ae^{-7x} + \frac{13}{2}e^{-\frac{x}{2}} - 7Ae^{7x} - 7Be^{-\frac{x}{2}} = 0[/tex]
[tex]98Ae^{-7x} - 91Ae^{-7x} - 7Be^{-\frac{x}{2}} + \frac{1}{2}Be^{\frac{x}{2}} + \frac{13}{2}e^{-\frac{x}{2}} - 7Be^{-\frac{x}{2}} = 0[/tex]
[tex]0A + 0B = 0[/tex]
[tex]0 = 0[/tex], thus, we found the identity, and for each constant A and B, the following is a solution.
--------------------------------------------------
Question b:
[tex]y = Ae^{7x} + Be^{-\frac{x}{2}}[/tex]
Since [tex]y(0) = 3[/tex][tex]A + B = 3 \rightarrow B = 3 - A[/tex]
--------------------------------------------------
[tex]y^{\prime} = 7Ae^{-7x} - \frac{1}{2}Be^{-\frac{x}{2}}[/tex]
Since [tex]y^{\prime}(0) = -5[/tex][tex]7A - \frac{1}{2}B = -5[/tex]
Using [tex]B = 3 - A[/tex]
[tex]7A - \frac{3}{2} + \frac{A}{2} = -5[/tex]
[tex]\frac{14A}{2} + \frac{A}{2} = -\frac{10}{2} + \frac{3}{2}[/tex]
[tex]\frac{15A}{2} = -\frac{7}{2}[/tex]
[tex]15A = -7[/tex]
[tex]A = -\frac{7}{15}[/tex]
--------------------------------------------------
Then, B is given by:
[tex]B = 3 - A = 3 - (-\frac{7}{15}) = \frac{45}{15} + \frac{7}{15} = \frac{52}{15}[/tex]
Thus, the values are: [tex]A = -\frac{7}{15}, B = \frac{52}{15}[/tex]
A similar problem is given at https://brainly.com/question/2456414
Yooooo HELPPP
with this question plz
Answer:
Step-by-step explanation:
(x-2)(x+4)=x^2+4x-2x-8=0=> x =2, x=0
Answer:
A
Step-by-step explanation:
Five hundred randomly selected adult residents in Sacramento are surveyed to determine whether they believe children should have limited smartphone access. Of the 500 people surveyed, 381 responded yes - they believe children should have limited smartphone access.
You wish to estimate a population mean y with a known population standard devi- ation o = 3.5. If you want the error bound E of a 95% confidence interval to be less than 0.001, how large must the sample size n be?
Answer:
The sample size must be of 47,059,600.
Step-by-step explanation:
We have to find our [tex]\alpha[/tex] level, that is the subtraction of 1 by the confidence interval divided by 2. So:
[tex]\alpha = \frac{1 - 0.95}{2} = 0.025[/tex]
Now, we have to find z in the Z-table as such z has a p-value of [tex]1 - \alpha[/tex].
That is z with a p-value of [tex]1 - 0.025 = 0.975[/tex], so Z = 1.96.
Now, find the margin of error M as such
[tex]M = z\frac{\sigma}{\sqrt{n}}[/tex]
In which [tex]\sigma[/tex] is the standard deviation of the population and n is the size of the sample.
Standard deviation:
[tex]\sigma = 3.5[/tex]
If you want the error bound E of a 95% confidence interval to be less than 0.001, how large must the sample size n be?
This is n for which M = 0.001. So
[tex]M = z\frac{\sigma}{\sqrt{n}}[/tex]
[tex]0.001 = 1.96\frac{3.5}{\sqrt{n}}[/tex]
[tex]0.001\sqrt{n} = 1.96*3.5[/tex]
[tex]\sqrt{n} = \frac{1.96*3.5}{0.001}[/tex]
[tex](\sqrt{n})^2 = (\frac{1.96*3.5}{0.001})^2[/tex]
[tex]n = 47059600[/tex]
The sample size must be of 47,059,600.
Suppose that a local TV station conducts a survey of a random sample of 120 registered voters in order to predict the winner of a local election. The Democrat candidate was favored by 62 of the respondents.
Required:
a. Construct and interpret a 99% CI for the true proportion of voters who prefer the Republican candidate.
b. If a candidate needs a simple majority of the votes to win the election, can the Republican candidate be confident of victory? Justify your response with an appropriate statistical argument.
Answer:
a) The 99% CI for the true proportion of voters who prefer the Republican candidate is (0.3658, 0.6001). This means that we are 99% sure that the true population proportion of all voters who prefer the Republican candidate is (0.3658, 0.6001).
b) The upper bound of the confidence interval is above 0.5 = 50%, which meas that the candidate can be confidence of victory.
Step-by-step explanation:
Question a:
In a sample with a number n of people surveyed with a probability of a success of [tex]\pi[/tex], and a confidence level of [tex]1-\alpha[/tex], we have the following confidence interval of proportions.
[tex]\pi \pm z\sqrt{\frac{\pi(1-\pi)}{n}}[/tex]
In which
z is the z-score that has a p-value of [tex]1 - \frac{\alpha}{2}[/tex].
Sample of 120 registered voters in order to predict the winner of a local election. The Democrat candidate was favored by 62 of the respondents.
So 120 - 62 = 58 favored the Republican candidate, so:
[tex]n = 120, \pi = \frac{58}{120} = 0.4833[/tex]
99% confidence level
So [tex]\alpha = 0.01[/tex], z is the value of Z that has a p-value of [tex]1 - \frac{0.01}{2} = 0.995[/tex], so [tex]Z = 2.575[/tex].
The lower limit of this interval is:
[tex]\pi - z\sqrt{\frac{\pi(1-\pi)}{n}} = 0.4833 - 2.575\sqrt{\frac{0.4833*0.5167}{120}} = 0.3658[/tex]
The upper limit of this interval is:
[tex]\pi + z\sqrt{\frac{\pi(1-\pi)}{n}} = 0.4833 + 2.575\sqrt{\frac{0.4833*0.5167}{120}} = 0.6001[/tex]
The 99% CI for the true proportion of voters who prefer the Republican candidate is (0.3658, 0.6001). This means that we are 99% sure that the true population proportion of all voters who prefer the Republican candidate is (0.3658, 0.6001).
b. If a candidate needs a simple majority of the votes to win the election, can the Republican candidate be confident of victory? Justify your response with an appropriate statistical argument.
The upper bound of the confidence interval is above 0.5 = 50%, which meas that the candidate can be confidence of victory.
A solid is formed by rotating the region bounded by y = x − x^2 and y = 0 about the line x = 2 . Use the shell method to find the volume of the solid.
Answer:
The volume of the resulting solid is π/2 cubic units.
Step-by-step explanation:
Please refer to the diagram below.
The shell method is given by:
[tex]\displaystyle V = 2\pi \int _a ^b r(x) h(x)\, dx[/tex]
Where the representative rectangle is parallel to the axis of revolution, r(x) is the distance from the axis of revolution to the center of the rectangle, and h(x) is the height of the rectangle.
From the diagram, we can see that r(x) = (2 - x) and that h(x) is simply y. The limits of integration are from a = 0 to b = 1. Therefore:
[tex]\displaystyle V = 2\pi \int_0^1\underbrace{\left(2-x\right)}_{r(x)}\underbrace{\left(x - x^2\right)}_{h(x)}\, dx[/tex]
Evaluate:
[tex]\displaystyle \begin{aligned} V&= 2\pi \int_0 ^1 \left(2x-2x^2-x^2+x^3\right) \, dx\\ \\ &= 2\pi\int _0^1 x^3 -3x^2 + 2x \, dx \\ \\ &= 2\pi\left(\frac{x^4}{4} - x^3 + x^2 \Bigg|_0^1\right) \\ \\ &= 2\pi \left(\frac{1}{4} - 1 + 1 \right) \\ \\ &= \frac{\pi}{2}\end{aligned}[/tex]
The volume of the resulting solid is π/2 cubic units.
Answer:
pi/2
Step-by-step explanation:
I always like to draw an illustration for these problems.
For shells method think volume of cylinder=2pi×r×h
Integrate(2pi(2-x)(x-x^2) ,x=0...1)
Multiply
Integrate(2pi(2x-2x^2-x^2+x^3 ,x=0...1)
Combine like terms
Integrate(2pi(2x-3x^2+x^3) ,x=0...1)
Begin to evaluate
2pi(2x^2/2-3x^3/3+x^4/4) ,x=0...1
2pi(x^2-x^3+x^4/4), x=0...1
2pi(1-1+1/4)
2pi/4
pi/2
PLSSS HELPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPP
Answer:
I believe its EG and NE but i might be wrong
Step-by-step explanation:
POUILO 11. For a bivariate frequency table having (p + q) classification the total number of cells is
(a) p (b) p +q (c) q (d) pq
Answer:
g
Step-by-step explanation:
f