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2 years ago

Does each situation describe a survey, an experiment, or an observational study?

Mathematics

2 answers:

lions [1.4K]2 years ago

5 0

Patients who visit a clinic for the first time are asked to answer 15 questions about their health history.

Survey

A researcher randomly chooses 20 patients who come to the clinic with the flu and gives them an experimental drug. A randomly chosen group of 20 patients who come in with the flu receive a placebo.

Experiment

A doctor at the clinic asks patients who come in with a headache how many hours of sleep they get on a typical night.

Observational Study

vampirchik [111]2 years ago

5 0

Answer:

A survey : survey sampling is the process of selecting a sample of elements from a target population to conduct any survey.

An experiment : an experiment is a procedure that can be infinitely repeated and can have many possible outcomes.

An observational study - observational studies are done to understand cause and effect relationships.

Survey - Patients who visit a clinic for the first time are asked to answer 15 questions about their health history.

Experiment - A researcher randomly chooses 20 patients who come to the clinic with the flu and gives them an experimental drug. A randomly chosen group of 20 patients who come in with the flu receive a placebo.

Observational Study - A doctor at the clinic asks patients who come in with a headache how many hours of sleep they get on a typical night.

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A circle has an area of 2511 square centimeters. What is the length of its<br> radius?

romanna [79]

Answer:

r=28.27 cm aprox

Step-by-step explanation:

Well you know that the area of a circle is A= $\pi$ $r^{2}$ so

2511= $\pi$ $r^{2}$ so

$r^{2}$ =2511/ $\pi$

r=28.27 cm aprox

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3 years ago

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Evaluate the surface integral ModifyingBelow Integral from nothing to nothing Integral from nothing to nothing With Upper S f (x

kykrilka [37]

Parameterize $S$ by

$\vec s(u,v)=6\cos u\sin v\,\vec\imath+6\sin u\sin v\,\vec\jmath+6\cos v\,\vec k$

with $0\le u\le2\pi$ and $0\le v\le\frac\pi2$ . Take a normal vector to $S$ ,

$\dfrac{\partial\vec s}{\partial v}\times\dfrac{\partial\vec s}{\partial u}=36\cos u\sin^2v\,\vec\imath+36\sin u\sin^2v\,\vec\jmath+36\cos v\sin v\,\vec k$

which has norm

$\left\|\dfrac{\partial\vec s}{\partial v}\times\dfrac{\partial\vec s}{\partial u}\right\|=36\sin v$

Then the integral of $f(x,y,z)=x^2+y^2$ over $S$ is

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3 years ago

Which expression is equivalent to 7(p+2n)+n?

Illusion [34]

We actually need the choices but oh well, we can simpify and hopefuly it is one of the choices

remember the distributive property
a(b+c)=ab+ac
so

7(p+2n)+n
distribute first
7(p)+7(2n)+n
7p+14n+n
7p+15n is an equivilent expression

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3 years ago

Solve for x. Round to the nearest tenth, if necessary.

serg [7]

Answer:

x = 8.8

Step-by-step explanation:

take 20 degree as reference angle .the,

hypotenuse = OQ = x (hypotenuse is always opposite of 90 degree)

perpendicular(opposite) = PQ 3 (opposite of reference angle is perpendicular or also called as opposite)

base(adjacent) = OP (side which lies on the same line where 90 degree and reference angle)

using sin rule

sin 20 = opposite / hypotenuse

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x = 8.8

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2 years ago

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Lady_Fox [76]

X equals 16
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3 years ago