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dusya [7]
4 years ago
6

Determine whether the given description corresponds to an observational study or experiment

Mathematics
1 answer:
11111nata11111 [884]4 years ago
6 0

Answer:

The answer is A) The given description corresponds to an observational study.

Step-by-step explanation:

We can know that is an observational study because the definition of a observational studies are where researchers observe the effect of a risk factor, diagnostic test, treatment or other intervention without trying to change who is or isn't exposed to it.

In this case the researches are just monitoring the sleep of the students without altering anything.

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Jim is enclosing a rectangular garden with 170 feet of fencing. The length of the garden is 10 feet more than twice it’s width,
Darina [25.2K]

Answer:

1,500\ ft^2

Step-by-step explanation:

Let

L ----> the length of the rectangular garden in feet

w ---> the width of  the rectangular garden in feet

step 1

Find the width

we know that

The perimeter of the rectangular garden is

P=2(L+W)

P=170\ ft

so

170=2(L+W)

Simplify

85=(L+W) ----> equation A

L=2W+10 ----> equation B

substitute equation B in equation A and solve for W

85=(2W+10+W)

85-10=3W

3W=75

W=25\ ft

Find the value of L

L=2(25)+10=60\ ft

step 2

Find the area

we know that

The area of the rectangular garden is

A=(LW)

substitute the values

A=(60)(25)=1,500\ ft^2

6 0
3 years ago
X² + 3x – 7=0<br> Solve<br> X= or x=
svetoff [14.1K]

Answer:

x = 2

Step-by-step explanation:

X² = 3x - 7 = 0

X² = 3x = 7

(x + 1) (x + 2) = 7

(x + 1) + x = 7 - 2

x + x = 7 - 3

2x = 4

x = 4/2

x = 2

8 0
3 years ago
Let A = {the Rationals) and B = {the Irrationals). Find AU B.
anzhelika [568]

Answer:

Option B.

Step-by-step explanation:

It is given that

A = {The Rationals}

B = {The Irrationals}

We need to find the set A∪B.

If we have two sets X and Y then union of these sets (X∪Y) contains all the elements of set X, of set Y or both.

It is given that A is the set of rations and B is the set of irrational, so the union A∪B is the combined set of all rational or irrational numbers.

A∪B = {The Rationals} +  {The Irrationals}

A∪B = {The Reals}

Therefore, the correct option is B.

4 0
3 years ago
Find the 78th term of the arithmetic sequence<br> -12,-13,-14,
creativ13 [48]

Answer:

  -89

Step-by-step explanation:

The first term of the sequence is a1 = -12.

The common difference between terms is ...

  d = -13 -(-12) = -1

The generic term is given by ...

  an = a1 +d(n -1)

Then the 78th term is ...

  a78 = -12 +(-1)(78 -1) = -12 -77

  a78 = -89

8 0
2 years ago
If there were 45 cars In a line that stretched 454 feet, what is the average car length?
jolli1 [7]

45 cars=454

Divide 45 on both sides to get the average length of a single car

1 car = 10.01 ft

7 0
3 years ago
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