Ask question

Ask question

All categories

2 years ago

10

An energy drink company claims that its product increases students' memory levels. To support its claims, the company issues adv

ertisements claiming that 8 out of 10 people (chosen randomly from across the country) who tried their product reported improved memory. The missing component in this study is a
A) control group B) sample group C) population D) test group

2 answers:

dexar [7]2 years ago

8 0

A) control group, they did not also survey 10 other ppl who took a placebo

gladu [14]2 years ago

3 0

Answer: A) control group

Step-by-step explanation:

A control group is a group of participants who are used for comparing another group to in a test or experiment. It is composed of participants who do not receive the experimental treatment.

In the given situation an energy drink company claims that its product increases students' memory levels.

To support its claims, the company issues advertisements claiming that 8 out of 10 people (chosen randomly from across the country) who tried their product reported improved memory.

But they haven't compose a control group to compare the results for test.

You might be interested in

NO LINKS OR ANSWERING QUESTIONS YOU DON'T KNOW!!! THIS IS NOT A TEST OR AN ASSESSMENT!! Please help me with these math questions

Art [367]

Answer:

See below

Step-by-step explanation:

3. What are two ways that a vector can be represented?

Considering a vector $\vec{v}$ in some vector space $\mathbb R^n$ we have

$\vec{v} = \langle a,b\rangle$

This is the component form. I don't like that way. It is probably used in high school, but

$\vec{v} = \begin{pmatrix} a\\ b\\ \end{pmatrix}$

is preferable because the inner product on $\mathbb R^n$ is defined to be

$\langle a,b\rangle := \sum_{i = 1}^n a_i b_i$

You can also write it using linear form such as $\vec{v} = 2i+2j$

4.

For this question, I think you meant

vectors

$\vec{u_1} = (-8, 12)$

$\vec{u_2} = (13, 15)$

Once

$\cos(\theta)=\dfrac{\vec{u_1} \cdot\vec{u_2}}{||\vec{u_1}||||\vec{u_2}||}$

Considering that the dot product is

$\vec{u_1}\cdot \vec{u_2} = (-8)\cdot 13 + 12\cdot 15 = -104+180= 76$

and the norm of $\vec{u_1}$ is $||\vec{u_1}|| = \sqrt{(-8)^2 + 12^2} = \sqrt{64 + 144}= \sqrt{208}$

and the norm of $\vec{u_2}$ is $||\vec{u_2}|| = \sqrt{13^2 + 15^2} = \sqrt{169 + 225}= \sqrt{394}$

Thus,

$\cos(\theta)=\dfrac{76}{\sqrt{208} \sqrt{394}} = \dfrac{19}{\sqrt{13}\sqrt{394}}=\dfrac{19}{\sqrt{5122}}$

$\therefore \theta = \arccos \left(\dfrac{19}{\sqrt{5122}} \right)$

3 0

2 years ago

Two pages that face each other in a book have 421 as the sum of their page numbers. What is the number of the page that comes fi

nordsb [41]

Answer:the pages will come on the first is 210

Explanation:

Since we have given that two pages that face each other in a book

i.e. they must be consecutive to each other

so, let the first page number be x

and the second page number be x+1

According to question,

$x+x+1=421\\2x+1=421$

2x=421 -1

2x=420

$x=\frac{420}{2}\\=210$

So, the pages will come on the first is 210

4 0

2 years ago

Jason rolls a fair number cube labeled 1 through 6, and then he flips a coin. What is the probability that he rolls a 3 and flip

qwelly [4]

The answer is 1/12

The chance of getting a 3 on a six-sided dice is 1/6

The possibility of getting heads on a two-sided coin is 1/2

6 multiplied by 2 is 12

1 multiplied by 1 is 1

Hope it helps!

3 0

2 years ago

Read 2 more answers

Which simplifications of the powers of i are correct? There may be more than one correct answer.

fredd [130]

$\bf i^2=-1\qquad\qquad i^3=-i\qquad \qquad i^4=1 \\\\[-0.35em] \rule{34em}{0.25pt}\\\\ i^{22}\implies i^{(4\cdot 5)+2}\implies i^{4\cdot 5}i^2\implies (i^4)^5 i^2\implies 1^5(-1)\implies -1~\dotfill \bigotimes \\\\\\ i^{11}\implies i^{(2\cdot 5)+1}\implies (i^2)^5 i\implies (-1)^5(i)\implies -i~\dotfill \checkmark$

$\bf i^{21}\implies i^{(4\cdot 5)+1}\implies (i^4)^5 i\implies 1^5(i)\implies i~\dotfill \checkmark \\\\\\ i^{12}\implies i^{3\cdot 4}\implies i^3 i^4\implies (-i)(1)\implies -i\dotfill \bigotimes \\\\\\ i^{20}\implies i^{4\cdot 5}\implies (i^4)^5\implies 1~\dotfill \checkmark \\\\\\ i^{26}\implies i^{(4\cdot 6)+2}\implies (i^4)^6 i^2\implies 1^6(-1)\implies -1\dotfill \checkmark \\\\\\ i^{27}\implies i^{(4\cdot 6)+3}\implies (i^4)^6 i^3 \implies 1^6(-i)\implies -i\dotfill \bigotimes$

6 0

2 years ago

Your job as investigator is to determine who caused this accident. Is the driver responsible , or is the farmer responsible? Rea

ziro4ka [17]

It’s 6 i’m pretty sure, your welcome have a good day

3 0

2 years ago