Answer:
may not be exact
1- surveying every fifth student who walks in
2-randomly selected people of both genders
3-asking 8 random students from each second period
4-asking 4 girls and 4 boys from each~~
5-randomly choosing a page and counting the words
Step-by-step explanation:
1-explanation; the first one is skewed two 7th graders, the third one is skewed to volleyball players, the fourth one is skewed to eight graders
Help me please :(( ......
Answer:
1. Last years middle school and highschool softball teams.
2. I can't see the last option
3. Every girl at the local middle school.
4. A group of students at a college.
5. Survey the students selected blindly put of a box containing every students names.
Step-by-step explanation:
I hope these are correct. comment the last option for #2.
Will give brainliest pls answer!!
Find the volume of the rectangular
prism.
A)29 cm³
B) 87 cm³
C)288 cm³
D)576 cm³
Answer:
D) 576 cubic cm
Step-by-step explanation:
[tex]16 \times 9 \times 4 = 576[/tex]
Answer:
the answer is D
Step-by-step explanation:
volume =height × length × width
so 9×4×16= 576
Can you solve for x please? this one has me by the balls.
Answer:
42.5
Step-by-step explanation:
(180-95)÷2=42.5
Answer all 6 pictures/questions !!
Answer:
See below for answers and explanations
Step-by-step explanation:
Problem 1
First, identify the three vectors in component form (remember to have the direction angle for each vector account for the quadrants they are in!):
[tex]u=\langle90\cos220^\circ,90\sin220^\circ\rangle\\v=\langle 60\cos110^\circ,60\sin110^\circ\rangle\\w=\langle 40\cos30^\circ,40\sin30^\circ\rangle[/tex]
Secondly, we add them:
[tex]u+v+w=\langle90\cos220^\circ+60\cos110^\circ+40\cos30^\circ,90\sin220^\circ+60\sin110^\circ+40\sin30^\circ\rangle\approx\langle-54.824,18.531\rangle[/tex]
Thirdly, find the magnitude of the new vector:
[tex]||u+v+w||=\sqrt{(-54.824)^2+(18.531)^2}\\||u+v+w||\approx57.871[/tex]
And finally, find the direction of the new vector:
[tex]\theta=tan^{-1}(\frac{18.531}{-54.824})\\\theta\approx-18.675^\circ\approx-19^\circ[/tex]
Because our new vector is in Quadrant II, our found direction angle is a reference angle, telling us that the actual direction of our vector is 19° clockwise from the negative x-axis, which would be 180°-19°=161°
Thus, B is the best answer
Problem 2
To find the component form of a vector, we simply subtract the initial point from the terminal point. In this case, our initial point is at (7,-1) and our terminal point is at (1,6). We subtract the horizontal and vertical components separately:
[tex]\langle1-7,6-(-1)\rangle=\langle-6,7\rangle[/tex]
Thus, A is the correct answer
Problem 3
Again, subtract the initial point from the terminal point to find the vector, and then apply scalar multiplication:
[tex]-\frac{1}{2}v=-\frac{1}{2} \langle-8-8,10-4\rangle=-\frac{1}{2}\langle-16,6\rangle=\langle8,-3\rangle[/tex]
Thus, C is the correct answer
Problem 4 (top one in 4th image)
Remember that scalar multiplication only affects the magnitude of the vector and not the direction. Thus, [tex]-3u=-3\bigr[20\langle\cos30^\circ,\sin30^\circ\rangle\bigr]=-60\langle\cos30^\circ,\sin30^\circ\rangle[/tex], which means our magnitude is -60 and our direction remains 30°.
Thus, B is the correct answer
Problem 5 (fake #6, bottom one in 4th image)
Basically, whatever is in front of the i represents the horizontal component, and whatever is in front of the j represents the vertical component, so:
[tex]u=-3i+8j=\langle-3,8\rangle[/tex]
Thus, B is the correct answer
Problem 6 (real one, 5th image)
Recall:
Two vectors are said to be orthogonal if their dot product is 0 and are perpendicular to each other (form a 90° angle)Two vectors are said to be parallel if the angle between the vectors is 0° or 180° i.e. cosθ=-1Knowing these facts, let us compute the dot product:
[tex]u\cdot v=(-4*28)+(7*-49)=(-112)+(-343)=-455[/tex]
Since the dot product of the two vectors is not 0, then the vectors are not orthogonal, so we can eliminate choices A and B
To check if the vectors are parallel, find the angle between them:
[tex]\displaystyle\theta=cos^{-1}\biggr(\frac{u\cdot v}{||u||\:||v||}\biggr)\\\\\theta=cos^{-1}\biggr(\frac{-455}{\sqrt{(-4)^2+(7)^2}\sqrt{(28)^2+(-49)^2}}\biggr)\\\\\theta=cos^{-1}\biggr(\frac{-455}{\sqrt{16+49}\sqrt{784+2401}}\biggr)\\\\\theta=cos^{-1}\biggr(\frac{-455}{\sqrt{65}\sqrt{3185}}\biggr)\\\\\theta=cos^{-1}\biggr(\frac{-455}{\sqrt{207025}}\biggr)\\\\\theta=cos^{-1}\biggr(\frac{-455}{455}\biggr)\\\\\theta=cos^{-1}(-1)\\\\\theta=180^\circ[/tex]
So, since the angle between the two vectors is 180°, this implies that cosθ=-1, and the two vectors must be parallel.
Thus, D is the correct answer
Which of the following are not polynomials?
Answer:
D
I really wish is right!!!
The diameter of a cylindrical construction pipe is 5 ft. If the pipe is 25 ft long, what is its volume?
Answer:
490.87 ft^3.
Step-by-step explanation:
Radius = 1/2 * 5 = 2.5 ft.
Volume = π r^2 L
= π*2.5^2*25
= 490.87 ft^3
Roberto has by saltine crackers at the store. The label on the shelf for brand A says that it’s unit cost is $3.75/lb. Brand B says that its unit cost is $0.18/oz. Which is the better by?
Answer:
Brand A
Step-by-step explanation:
IN the end buying it for $3.75/lb would end up being cheaper then buying it for $0.18/oz. Hopethis helps!
What is If a = 3, then 2ª=
Answer:
2^3 = 2 * 2 * 2 which equals 8
Step-by-step explanation:
sets of linear systems wherein there is one Consistent & Dependent, Consistent & Independent, and one Inconsistent.
Answer:
What is the difference between entering a formula and entering data ??
You spin a spinner numbered from 1 to 6 and spin another spinner with the colors violet and yellow. Both spinners are divided into sections with the same area. How many possible outcomes are in the sample space?
which expression is equivalent to
Answer:
Option D
Step-by-step explanation:
[tex]6\dfrac{3}{5}*\dfrac{5}{8}=\dfrac{5}{8}*6\dfrac{3}{5}[/tex]
Poperty : Commutative property of multiplication.
When two numberes are multiplied, changing the order of numbers will not change the result.
Which equation represents a line which is perpendicular to the line y = – 4/5+ 2
5x + 4y = 28
4x - 5y =-25
4y – 5x = -12
4x + 5y = -30
How do you write 0.92 as a percentage?
the width of a rectangle is a third as long as the length. If the primeter is 24 inches, what is the area of the rectangle?
Answer:
108 inches
Step-by-step explaination:
Looking at the picture I drew, we can assume that 24 = 4x
and so x=6 and 3x=18.
6 times 18 is 108.
URGENT I HAVE ALMOST 0 TIME LEFT I NEED LAST MINUTE HELP
A parabola has zeros of 7 and 1 and passes through the point (3,4). Determine the equation of the parabola.
Answer:
The zeros are the points where the parabola intercepts the x-axis.
[tex]\sf x = 7 \implies x - 7 = 0[/tex]
[tex]\sf x = 1 \implies x - 1 = 0[/tex]
[tex]\sf \implies y = a(x - 7)(x - 1)[/tex] where a is some constant
If the parabola passes through point (3, 4) then:
[tex]\sf \implies a(3 - 7)(3 - 1) = 4[/tex]
[tex]\sf \implies a(-4)(2) = 4[/tex]
[tex]\sf \implies -8a = 4[/tex]
[tex]\sf \implies a = -\dfrac12[/tex]
So the equation of the parabola is:
[tex]\sf y = -\dfrac12(x - 7)(x - 1)[/tex]
Or in standard form:
[tex]\sf y = -\dfrac12x^2+4x-\dfrac72[/tex]
Spot the quadratic equation:-
(x-1)(x-7)x(x-7)-1(x-7)x²-7x-x+7x²-8x+7Find a through (3,4)
a(x²-8x+7)=4a(9-24+7)=4a(-8)=4a=-1/2Equation:-
y=-1/2(x-7)(x-1)=
15. Given a rectangle ABCD with AD 12. The diagonals AC and BD intersect at point O such that
mZDOC = 30°. Find the area of the rectangle.
Answer:
To find the area, we need to find the side length AB (and DC).
The easiest way to approach this is to draw a sketch with all the given information (see attached).
As point O is the center point of the rectangle, we can draw a horizontal line from point O to the center point of BC (point M on the diagram) and create a right triangle. We can then use the Sine rule to find the shortest leg of the triangle (marked as x on the diagram). This will be half of the side length AB, and so to find the side length, simply multiply it by 2.
To find the missing angles of the right triangle:
m∠COM = (180° - 30°) ÷ 2 = 75°
m∠OCM = 180° - 90° - m∠COM = 90° - 75° = 15°
Sine rule
[tex]\sf \dfrac{a}{sinA}=\dfrac{b}{sinB}=\dfrac{c}{sinB}[/tex]
(where A, B and C are the angles and a, b and c are the sides opposite the angles)
[tex]\implies \dfrac{x}{\sin(15)}=\dfrac{6}{\sin(75)}[/tex]
[tex]\implies x=\sin(15)\cdot \dfrac{6}{\sin(75)}[/tex]
[tex]\implies x=12-6\sqrt{3}[/tex]
As AB = [tex]2x[/tex]
[tex]\begin{aligned} \implies AB & =2x\\ & =2(12-6\sqrt{3})\\ & =24-12\sqrt{3}\end{aligned}[/tex]
Now we have both side lengths of the rectangle, we can easily calculate the area.
Area of a rectangle = width × length
= (24 - 12√3) × 12
= 288 - 144√3
= 38.5846837...
= 38.585 units² (nearest thousandth)
The expression cosine of pi over 2 times cosine of pi over 5 plus sine of pi over 2 times sine of pi over 5 can be rewritten as which of the following?
cosine of 7 times pi over 10
cosine of 3 times pi over 10
sine of 7 times pi over 10
sine of 3 times pi over 10
(The clear version of the question is in the picture below)
Answer:
(b) cos(3π/10)
Step-by-step explanation:
The given expression matches the trig identity form for the cosine of the difference of two angles:
cos(α-β) = cos(α)cos(β) +sin(α)sin(β)
__
To match the given expression exactly, we can choose ...
α = π/2
β = π/5
Then the difference is ...
α -β = π/2 -π/5 = (5/10)π -(2/10)π = 3π/10
The given expression can be shortened to ...
cos(3π/10)
__
Additional comment
Sometimes it can be difficult to remember when the signs in trig identities match, and when they differ. The fact that cosines of smaller angles have larger values can be a peg on which to hang that hat.
Find the axis of symmetry and the vertex of the graph of y = 3x2 −18x + 17.
x = 3; (3, −10)
x = −3; (−3, −17)
x = 6; (3, −18)
x = −6; (3, −10)
Answer:
Vertex of y = − 3 x 2 + 18 x − 13 Ans: Vertex (3, 14)
Step-by-step explanation:
Explanation: x-coordinate of vertex: x = ( − b 2 a ) = − 18 − 6 = 3 y-coordinate of vertex: y = f(3) = -27 + 54 - 13 = 14 x-coordinate of the axis of symmetry is the same as the x-coordinate of the vertex: x = 3
having issues with this question
Answer:
[tex]5q^8y^{16}\sqrt{5qy}[/tex]
Step-by-step explanation:
[tex]\sqrt{125q^{17}y^{33}} =\sqrt{5*5^2*q*q^{16}*y*y^{32}}=5q^8y^{16}\sqrt{5qy}[/tex]
HELP ME!!!! please....
The graph of f(x) = -x2 - 2x + 8 is shown. Which of the following describes all solutions for f(x)?
O(x -x2 - 2x + 8) for all real numbers
O(-4,0), (-1,9), (0, 8), (2.0)
O(-4.0), (2,0)
O(x, y) for all real numbers
Answer:
[tex]f(x) = -x^2 - 2x + 8[/tex]
y-intercept is when x = 0:
[tex]\implies f(0) = -(0)^2 - 2(0) + 8=8[/tex]
So the y-intercept is (0, 8)
x-intercepts are when f(x) = 0:
[tex]\implies f(x)=0[/tex]
[tex]\implies -x^2 - 2x + 8=0[/tex]
[tex]\implies x^2 + 2x - 8=0[/tex]
[tex]\implies x^2 - 2x + 4x - 8=0[/tex]
[tex]\implies x(x - 2) + 4(x-2)=0[/tex]
[tex]\implies (x+4)(x - 2)=0[/tex]
Therefore:
[tex]\implies (x+4)=0 \implies x=-4[/tex]
[tex]\implies (x-2)=0 \implies x=2[/tex]
So the x-intercepts are (-4, 0) and (2, 0)
The vertex is the turning point of the parabola. The x-value of the vertex is the x-value between the 2 zeros (x-intercepts).
Therefore, the x-value of the vertex is [tex]\sf \dfrac{x_1+x_2}{2}=\dfrac{-4+2}{2}=-1[/tex]
Substituting x = -1 into the function:
[tex]\implies f(-1) = -(-1)^2 - 2(-1) + 8=9[/tex]
So the vertex is (-1, 9)
The domain is the input values, so x = all real numbers.
The range is the output values, so the range is [tex]f(x)\leq 9[/tex]
Therefore, (-4, 0), (-1, 9), (0, 8) and (2, 0) are solutions of the function, HOWEVER they are not ALL the solutions.
All solutions of the function are:
[tex](x, -x^2 - 2x + 8)[/tex] for all real numbers of x
HELPPPPPP PLEASEEE PLEASEEEEEEEEEEEEEEEEEE
Answer:
31.63495408
Step-by-step explanation:
Find area of trinagles and semicurucles and then add up
Answer:
31.625 ft²Step-by-step explanation:
It is assumed we need to find the area of shaded figure.The figure comprises of two semicircles and a triangle.
The two semicircles add to one full circle with the diameter of 5 ft.
Area of circle
A = πr² = 3.14*(5/2)² = 19.625 ft²Area of triangle
A = 1/2bh = 1/2(6)(4) = 12 ft²Total area
19.625 + 12 = 31.625 ft²1dasd
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The probability that a randomly selected 25-year-old male will survive the year is 0.9984 according to a report on vital
statistics. If three randomly selected 25-year-old males are selected from the general population, explain how to find the
probability that all three will survive the year. Follow the rules for significant figures.
Answer:
0.9952076759
Step-by-step explanation:
Probability that all three survive
= 0.9984 × 0.9984 × 0.9984
= 0.9952076759
PLEASE HELP ILL GIVE FIVE STARS AND GIVE BRAINLIEST AND GIVE THANKS PLEASE HELP
Ray is x years old. His brother Ron is y years older than Ray.
What will the sum of their ages be in 5 years?
Answer: X+Y+5
Step-by-step explanation:
There is no single answer you have to write an equation.
Simplify using the order of operations.
9−4 ·5+6
we know that the multiplication comes first in the family then we start from left to right
4 x 5= 20
9-20 = -11
-11 + 6 = -5
there you go!
[tex]9 - 4 \times 5 + 6[/tex]
[tex]9 - 20 + 6[/tex]
[tex] - 11 + 6[/tex]
[tex] - 5[/tex]
what is the circumference of a circle with a diameter of 7 in
Answer:
22 inches
Step-by-step explanation:
Given:
Diameter - 7 inches Radius - 3.5 inchesCircumference of circle = πd , where d is the diameter of a circle.
= 22/7 * 7 inches
Circumference = 22 inches
Total price: The sales tax is 4.25% and the sales tax is $17.55, what is the purchase price? (Round to the nearest cent)
The purchase price is ________
The total price is__________ (Round to the nearest cent)
Answer:
Purchase price = $412.94 (nearest cent)
Total price = $430.49 (nearest cent)
Step-by-step explanation:
Purchase price
If 4.25% = $17.55
⇒ 100% = (17.55 ÷ 4.25) × 100 = 412.9411765...
⇒ Purchase price = $412.94 (nearest cent)
Total price
total price = purchase price + sales tax
= $412.94 + $17.55
= $430.49
So let the original price be x
4.25% of x=17.550.0425x=17.55x=17.55÷0.0425$412.94Total price:-
412.94+17.55$430.49The graph of y = StartAbsoluteValue x EndAbsoluteValue is transformed as shown in the graph below. Which equation represents the transformed function? On a coordinate plane, an absolute value function is shown. The vertex of the function is at (negative 3, negative 2). It crosses the x-axis at (negative 5, 0) and (negative 1, 0) and it crosses the y-axis at (0, 1). y = StartAbsoluteValue x minus 3 EndAbsoluteValue + 2 y = StartAbsoluteValue x + 3 EndAbsoluteValue minus 2 y = StartAbsoluteValue x minus 2 EndAbsoluteValue + 3 y = StartAbsoluteValue x + 2 EndAbsoluteValue minus 3
Using translation concepts, it is found that the equation of the transformed function is:
y = |x + 3| - 2.
What is a translation?A translation is represented by a change in the function graph, according to operations such as multiplication or sum/subtraction in it's definition.
The absolute value function is given by y = |x|, and has vertex at (0,0). After the transformations, the function has vertex (-3, -2), which means that:
It was shifted 3 units to the left, hence x -> x + 3.It was shifted 2 units down, hence y -> y - 2.Thus, the equation of the function is now given by:
y = |x + 3| - 2.
More can be learned about translation concepts at https://brainly.com/question/4521517
Answer:y = |x + 3| - 2.
Step-by-step explanation: B on edge
Martinez and grouse swimming pool is finally finished and all this left to do is fill it with water. Martinez family decides to fill their pool using their garden hose to save money even though they know it will take a really long time the swimming pool is 10 m long and 5 m wide and Martinez family wants to the water to be 2 m deep water from the garden holes flows at a rate of 2500 l or 2.5 m³ per hour how long will it take to fill the pool
Answer:
the answer ia true
Step-by-step explanation:
hope this helps