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3 years ago

20. Give an example of a controlled experiment and an observational study.

Mathematics

1 answer:

Kryger [21]3 years ago

5 0

Answer:

We do studies to gather information and draw conclusions. The type of conclusion we draw depends on the study method used:

In an observational study, we measure or survey members of a sample without trying to affect them.

In a controlled experiment, we assign people or things to groups and apply some treatment to one of the groups, while the other group does not receive the treatment.

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Prove the following limit. lim x → 5 3x − 8 = 7 SOLUTION 1. Preliminary analysis of the problem (guessing a value for δ). Let ε

Temka [501]

$\displaystyle\lim_{x\to5}3x-8=7$

means to say that for any given $\varepsilon>0$ , we can find $\delta$ such that anytime $|x-5|$ (i.e. the whenever $x$ is "close enough" to 5), we can guarantee that $|(3x-8)-7|$ (i.e. the value of $3x-8$ is "close enough" to the limit value).

What we want to end up with is

$|(3x-8)-7|=|3x-15|=3|x-5|$

Dividing both sides by 3 gives

$|x-5|$

which suggests $\delta=\dfrac\varepsilon3$ is a sufficient threshold.

The proof itself is essentially the reverse of this analysis: Let $\varepsilon>0$ be given. Then if

$|x-5|$

and so the limit is 7. QED

8 0

3 years ago

Lenz father is paying for a $20 meal. He has a 15%-off coupon on his meal. After the discount, a 7% sales tax is applied. How mu

-BARSIC- [3]

Answer:

18.19.

First you have to subtract 15 from 100, giving you 85%. You then multiple 85% to the $20, giving you $17. You then add the 7 to 100, giving you 1.07%, then you multiple that to the $17 and you end up with $18.19.

3 0

3 years ago

How do i find the surface area of the sphere??

gogolik [260]

Answer:

98 π R

Step-by-step explanation:

Surface area of sphere = 4 π R²

= 2 π R × 2 R

= 49 π × 2 R

= 98 π R

3 0

3 years ago

PLZ HELP,, WILL BE MUCH APPRECIATED!

docker41 [41]

Answer:

178cm

Step-by-step explanation:

x=180

y=160

0.4(x+y)+42 =

0.4(180 + 160) +42 =

0.4(340)+42=

136+42=

178cm

7 0

3 years ago

Someone answer this for me

Andru [333]

Answer:

2 3/4

Step-by-step explanation:

I think is the right answer hope it helps

3 0

3 years ago