Please solve this equation
Answer:
fggggg hasdnkuw
Step-by-step explanation:
For each of the studies described, explain whether the study was an observational study or a randomized experiment.
a. A group of 100 students was randomly divided, with 50 assigned to receive vitamin C and the remaining 50 to receive a placebo, to determine whether or not vitamin C helps to prevent colds.
b. A random sample of patients who received a hip transplant operation at Stanford University Hospital during 2000 to 2010 will be followed for 10 years after their operation to determine the success (or failure) of the transplant.
c. Volunteers with high blood pressure were randomly divided into two groups. One group was taught to practice meditation and the other group was given a low-fat diet. After 8 weeks, reduction in blood pressure was compared for the two groups.
Answer:
B
Step-by-step explanation:
B
A particular fruit's weights are normally distributed, with a mean of 275 grams and a standard deviation of 19 grams. If you pick one fruit at random, what is the probability that it will weigh between 244 grams and 305 grams?
Answer:
0.8913 = 89.13% probability that it will weigh between 244 grams and 305 grams.
Step-by-step explanation:
Normal Probability Distribution:
Problems of normal distributions can be solved using the z-score formula.
In a set with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the z-score of a measure X is given by:
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the p-value, we get the probability that the value of the measure is greater than X.
Mean of 275 grams and a standard deviation of 19 grams
This means that [tex]\mu = 275, \sigma = 19[/tex]
What is the probability that it will weigh between 244 grams and 305 grams?
This is the p-value of Z when X = 305 subtracted by the p-value of Z when X = 244.
X = 305
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
[tex]Z = \frac{305 - 275}{19}[/tex]
[tex]Z = 1.58[/tex]
[tex]Z = 1.58[/tex] has a p-value of 0.9429.
X = 244
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
[tex]Z = \frac{244 - 275}{19}[/tex]
[tex]Z = -1.63[/tex]
[tex]Z = -1.63[/tex] has a p-value of 0.0516
0.9429 - 0.0516 = 0.8913
0.8913 = 89.13% probability that it will weigh between 244 grams and 305 grams.
reflectiion across y=x
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Answer:
see attached
Step-by-step explanation:
The reflection across y=-x swaps the coordinates and negates both of them. The first-quadrant figure becomes a third-quadrant figure.
(x, y) ⇒ (-y, -x)
please help thx steps too
Step-by-step explanation:
IN first triangle multiplier factor is 4
and IN second triangle multiplier factor is
[tex] \frac{3}{2} [/tex]
PLEASE HELP ME WITH THIS ONE QUESTION
How many combinations without repetition are possible if n = 4 and r = 3?
A) 16
B) 12
C) 3
D) 4
Given:
[tex]n=4[/tex] and [tex]r=3[/tex].
To find:
The combinations without repetition are possible if [tex]n=4[/tex] and [tex]r=3[/tex].
Solution:
Combination of selecting r item from total n items is:
[tex]^nC_r=\dfrac{n!}{r!(n-r)!}[/tex]
We have [tex]n=4[/tex] and [tex]r=3[/tex]. By using the above formula, we get
[tex]^4C_3=\dfrac{4!}{3!(4-3)!}[/tex]
[tex]^4C_3=\dfrac{4\times 3!}{3!1!}[/tex]
[tex]^4C_3=4[/tex]
Therefore, the correct option is D.
Answer:
Step-by-step explanation:
I don't understand plz help
9514 1404 393
Answer:
x = 2
Step-by-step explanation:
Triangles QST and QSR are congruent, so angle QST is congruent to angle QSR.
(3x +24)° = 30°
3x = 6 . . . . . . . . . divide by °, subtract 24
x = 2 . . . . . . . . . . divide by 3
__
Additional comment
What matters here is the relationship between the two marked acute angles. The fact that point Q is equidistant from the sides of angle TSR tells you that QS is an angle bisector and the two angles have equal measures. (The definition of an angle bisector is that it is equidistant from the sides of the angle.)
Recognition that the two triangles are congruent is another way to see that the marked acute angles have the same measure. The triangle congruence can be claimed on the basis of the HL theorem, since both are right triangles, have the same hypotenuse (QS), and have legs (QT, QR) with the same measure.
There are 9 students in a class: 7 boys and 2 girls.
If the teacher picks a group of 3 at random, what is the probability that everyone in the group is a boy?
Answer: 9/7
Step-by-step explanation:
6. A company builds a model of its earning, and finds that its profit fits the linear model()=5―2500 Where p is the profit in dollars and q is the quantity of its product sold. a) Explain what the slope and y-intercept mean in the context of the problem. Be specific and answer in complete sentence. (2 points)
Answer:
The slope of 5 means that for each product sold, the profit increases by 5, and the intercept of -2500 means that if no products are sold, the company loses 2500.
Step-by-step explanation:
Linear function:
A linear function has the following format:
[tex]y = mx + b[/tex]
In which m is the slope, that is, by how much y changes for each unit of x, and b is the y-intercept, which is the values of y when x = 0.
In this question:
[tex]p(q) = 5q - 2500[/tex]
p is the profit in dollars and q is the quantity of its product sold.
a) Explain what the slope and y-intercept mean in the context of the problem.
The slope of 5 means that for each product sold, the profit increases by 5, and the intercept of -2500 means that if no products are sold, the company loses 2500.
A zoo is designing a giant bird cage consisting of a cylinder of radius rr feet and height hh feet with a hemisphere on top (no bottom). The material for the hemisphere costs 2020 per square foot and the material for the cylindrical sides costs 1010 per square foot; the zoo has a budget of 45004500. Find the values of rr and hh giving the birds the greatest space inside assuming the zoo stays within its budget. Note: surface of a cylinder's side 2πrh2πrh, surface of a sphere 4πr24πr2, volume of a cylinder's side πr2hπr2h, volume of a sphere 43πr343πr3
Answer:
r = 42,32 ft
h = 84.8 ft
Step-by-step explanation:
We are going to apply Lagrange multipliers method
The greatest space means maximum volume
V(cage) = Vol. of the cylinder + volume of the hemisphere
V(cylinder ) = π*r²*h
V(sphere) = (4/3)*π*r² ⇒ V(hemisphere) = (2/3)*π*r³
V(cage) = π*r²*h + (2/3)*π*r³
Associated costs:
Costs = cost of cylinder + cost of hemisphere
Area of the cylinder = Lateral area ( no bottom no top)
Area of the cylinder = 2*π*r*h
Area of hemisphere = 2*π*r²
A(r,h) = 2*π*r*h + 2*π*r²
C(r , h ) = 10* 2*π*r*h + 20* 2*π*r² C(r , h ) = 20*π*r*h + 40*π*r²
4500 = 20*π*r*h + 40*π*r²
20*π*r*h + 40*π*r² - 4500 = 0 20*π*r*h + 40*π*r² - 4500 = g(r,h)
V(cage) = π*r²*h + (2/3)*π*r³
δV/δr = 2*r*π*h + 2*π*r² δg(r,h)/δr = 20*π*h + 80*π*r
δV/δh = π*r² δg(r,h)/δh = 20*π*r
δV/δr = λ* δg(r,h)/δr
2*r*π*h + 2*π*r² = λ* 20*π*h + 80*π*r
2*r*π* ( h + r ) = 20*π* λ* ( h + 4*r)
r* ( h + r ) = 10*λ* ( h + 4*r) (1)
δV/δh = λ* δg(r,h)/δh
π*r² = 20*λ*π*r r = 20*λ (2)
20*π*r*h + 40*π*r² - 4500 = 0 (3)
We need to sole the system of equation 1 ; 2 ; 3
r = 20*λ plugging that value in equation 1
20*λ ( h + 20*λ ) = 10*λ* ( h + 4*r)
2( h + 20*λ ) = ( h + 4*20*λ)
2*h + 40*λ = h + 80*λ
h = 40*λ
20*π*r*h + 40*π*r² - 4500 = 0
20*π*20*λ*40*λ + 40*π+400λ² - 4500 = 0
16000*π*λ² + 16000*π*λ² = 4500
32000*π*λ² = 4500
320*π*λ² = 4500
λ² = 4500/1004,8 λ² = 4.48 λ = 2.12
Then
r = 20* λ r = 42,32 ft
h = 40* λ h = 84.8 ft
if a line intersect x axis at a point (6,0) and y axis at a point (0,-8). then what is equation of a line?
Answer: y = 4/3x -8
Step-by-step explanation:
(6,0) (0,-8)
0-(-8)/6-0 = 8/6 = 4/3
y intercept is given already
find the value of x if 3x over 2 equals to 3
Answer:
x = 2
Step-by-step explanation:
3x/2 = 3/1
cross-multiply to get:
3x = 6
divide each side by 2 to get:
x = 2
Can someone help me with this question please.
Answer:
The rule is to divide the weight of the bag by 4 to find the number of marbles.
Step-by-step explanation:
The rule is to divide the weight of the bag by 4 to find the number of marbles.
If 5^3b-1 = 5^b-3, what is the value of b?
-2
-1
1
2
Answer:
3b-1 = b-3
2b = 4
b = 2
Step-by-step explanation:
Let x be a real number such that x + (1/x) is an integer. Prove that (x^n) + 1/(x^n) is an integer for every positive integer n.
Answer:
sim eu também preciso desta respota
A local hamburger shop sold a combined total of 393 hamburgers and cheeseburgers on Thursday. There were 57 fewer cheeseburgers sold than hamburgers. How many hamburgers were sold on Thursday?
Answer:
H+C = 393
H - 57 = C
~~~~~~~~~~~~~~~~
H + H - 57 = 393
2H = 450
H = 225
C = 168
Step-by-step explanation:
What is the area of a sector when 0=90° and r= 8/3?
Answer:
16π/9
Step-by-step explanation:
the area of sector= ¼×π.r²
= ¼× π× (8/3)²
= ¼×64/9×π
= 16π/9
Answer:
Answer:
16π/9
Step-by-step explanation:
the area of sector= ¼×π.r²
= ¼× π× (8/3)²
= ¼×64/9×π
= 16π/9
Step-by-step explanation:
(a)A train completed a journey of 850 kilometres with an average speed of 80 km/hr.
Calculate, giving exact answers, the time taken for this journey in
(1)
hours,
hours, minutes and seconds.
(b)Another train took 10 hours 48 minutes to complete the same 850 km journey.
0 It departed at 19 20.
At what time, on the next day, did thsi train complete the journey?
Calculate the average speed, in kilometres per hour, for the journey.
drintinn
Answer:
a. 850/85 = 10.625 hr or 10 hr 37 min 30 sec
b. 6:08 AM
C. Average time is (10.625 + 10.8)/2 = 10.7125
or 10 hour 42 min 45 sec
Expand and simplify (n-2)(3n+7) + 2n(2n+3)
1. Determine the length and perimeter of Laura's property.
(5)
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Answer:
length: 40 mperimeter: 136 marea: 653 m²volume: 6.52 m³Step-by-step explanation:
1.The outer dimensions of the property are 20 squares (length) by 14 squares. Each square is 2 m on a side, so the overall length of the property is ...
(20 squares)×(2 m/square) = 40 m . . . . length
The overall width of the property is ...
(14 squares)×(2 m/square) = 28 m . . . . width
Then the perimeter is ...
P = 2(length + width) = 2(40 +28) m = 136 m . . . . perimeter
__
Additional comment
We have computed the perimeter as though the plot were a rectangle. If you carefully consider the total length of horizontal edges and the total length of vertical edges, you see that those totals are the same as they would be for a 20×14 square (40×28 m) rectangle.
_____
2.The area of open ground is perhaps most easily computed by finding the area that must be subtracted from the overall 20×14 square rectangle. Those exclusions will be (in dimensions of squares) ...
lower right corner: 8 wide by 3 high = 24 squaresfish pond: 2 wide by 3 high = 6 squaresveranda: 4 wide by 4 high = 16 squareshouse: 9 wide by 7 high = 63 squarespavement: 4 wide by 2 high = 8 squaresThe total area of exclusions is 24+6+16+63+8 = 117 squares. The bounding rectangle is 20 by 14 = 280 squares, so the open ground is ...
280 squares - 117 squares = 163 squares
At (2 m)(2 m) = 4 m² per grid square, that's an area of ...
(163 squares)(4 m²/square) = 652 m²
The surface area of the open ground is 652 m².
_____
3.The volume is given by the formula ...
V = Bh
where B is the base area and h is the height.
1 cm = 1/100 m = 0.01 m thickness. That means the total volume is ...
V = (652 m²)(0.01 m) = 6.52 m³
6.52 cubic meters of topsoil are needed to cover the open ground to a depth of 1 cm.
Can you help me on this?
Answer:
ez 1 + 1 = 1 is the correct answer
Please help me solve this. I keep getting the answer weong
Answer:
21 is the answer I think sike I lied ik its not im just trying get this over with
You can use this formula to work out the area of a triangle when you know two sides and the angle inbwtween them :
1/2 x a x b x sin(C)
where a and b are the two sides you know and C is the angle in between them.
So here a = 7, b = 14, C = 125.
Area = 1/2 x 7 x 14 x sin(125) = 40.138...
= 40.1 (nearest 10th)
Which of the following best represents the relationship between functions f and g?
g(x) = -f(x) - 1
g(x) = f(x - 1)
g(x) = -f(x) + 1
g(x) = -f(x)
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Answer:
(c) g(x) = -f(x) +1
Step-by-step explanation:
We really only need to consider one point on f(x) and/or g(x). We can look at the y-intercepts.
f(0) = 4 and g(0) = -3
Looking at the answer choices, we see ...
A. -f(0) -1 = -4 -1 = -5 ≠ g(0)
B. f(0 -1) = f(-1) = 1 ≠ g(0)
C. -f(0) +1 = -4 +1 = -3 = g(0) . . . . . matches requirements
D. -f(0) = -4 ≠ g(0)
The relation between f(x) and g(x) is g(x) = -f(x) +1.
can someone help me with this?
Answer: 22
Step-by-step explanation: 44:2=22
Which statement is true.?
Answer:
B
Step-by-step explanation:
NEED HELP ASAP!!!!!!
Answer:
It's a rhombus (if you can check more than one answer, it's also a parallelogram).
Step-by-step explanation:
A rhombus is a flat shape with 4 straight sides that are all equal length.
Also opposite sides are parallel and opposite angles are equal.
It is a type of parallelogram.
Answer:
It's a rhombus
Step-by-step explanation:
because all the 4 sides are equal
And it's like a square that it's top has been pushed
Researchers believe that 24.5% of the adults in the United States are obese. A Gallup poll examined the rate of obesity in America with a survey 86,664 randomly sampled U.S. adults. Of the adults surveyed, 23,053 said that they were obese. Is this enough evidence to state that more than 24.5% of all adults in the U.S. are obese
Answer:
The p-value of the test is 0 < 0.05(standard significance level), which means that this is enough evidence to state that more than 24.5% of all adults in the U.S. are obese
Step-by-step explanation:
Researchers believe that 24.5% of the adults in the United States are obese. Test if there is enough evidence to state that more than 24.5% of all adults in the U.S. are obese.
At the null hypothesis, we test if the proportion is of 24.5% or less, that is:
[tex]H_0: p \leq 0.245[/tex]
At the alternative hypothesis, we test if this proportion is greater than 24.5%, that is:
[tex]H_1: p > 0.245[/tex]
The test statistic is:
[tex]z = \frac{X - \mu}{\frac{\sigma}{\sqrt{n}}}[/tex]
In which X is the sample mean, [tex]\mu[/tex] is the value tested at the null hypothesis, [tex]\sigma[/tex] is the standard deviation and n is the size of the sample.
0.245 is tested at the null hypothesis:
This means that [tex]\mu = 0.245, \sigma = \sqrt{0.245*0.755}[/tex]
Survey 86,664 randomly sampled U.S. adults. Of the adults surveyed, 23,053 said that they were obese.
This means that [tex]n = 86664, X = \frac{23053}{86664} = 0.266[/tex]
Value of the test statistic:
[tex]z = \frac{X - \mu}{\frac{\sigma}{\sqrt{n}}}[/tex]
[tex]z = \frac{0.266 - 0.245}{\frac{\sqrt{0.245*0.755}}{\sqrt{86664}}}[/tex]
[tex]z = 14.37[/tex]
P-value of the test and decision:
The p-value of the test is the probability of finding a sample proportion of 0.266 or higher, which is 1 subtracted by the p-value of z = 14.37.
The p-value of z = 14.37 is 1.
1 - 1 = 0
The p-value of the test is 0 < 0.05(standard significance level), which means that this is enough evidence to state that more than 24.5% of all adults in the U.S. are obese
What is the y-intercept of this quadratic function? f(x)= -x^2
Answer:
x-intercept(s):
( 0 , 0 )
y-intercept(s):
( 0 , 0 )
Step-by-step explanation:
Answer:
(0,0)
Step-by-step explanation:
This has no real starting point. The x-intercept as well as the y-intercept is (0,0).
4n-6 in as a undistributed expression
Answer:
2( 2n-3)
Step-by-step explanation:
4n-6
2*2 n - 2*3
Factor out the greatest common factor
2( 2n-3)
Reflect (-3, 4) across the y-axis. Then reflect the result across the x-axis.