Answer:
Is an experimental study
Step-by-step explanation:
In an observational study you don't control any aspect of the investigation you just observe the variables that you determined since the beginning without any intervention.
In this case you are controlling who sees one or the other video, then you are controlling one of the variables that is the type of video each group sees and because of this it is an experimental study. Researchers designed an experiment to prove the null hypothesis they had.
Answer:
In mathematics, a theorem is a non-self-evident statement that has been proven to be true, either on the basis of generally accepted statements such as axioms or on the basis of previously established statements such as other theorems. A theorem is hence a logical consequence of the axioms, with a proof of the theorem being a logical argument which establishes its truth through the inference rules of a deductive system. As a result, the proof of a theorem is often interpreted as justification of the truth of the theorem statement. In light of the requirement that theorems be proved, the concept of a theorem is fundamentally deductive, in contrast to the notion of a scientific law, which is experimental.
Step-by-step explanation:
Answer:
<u>Width = 7 inches</u>
<u>Length = 23 inches</u>
Step-by-step explanation:
Let :
Equating to area :
- (2x + 9)(x) = 161
- 2x² + 9x = 161
- 2x² + 9x - 161 = 0
- 2x² - 14x + 23x - 161 = 0
- 2x(x - 7) + 23(x - 7) = 0
- x - 7 = 0
- x = 7
Dimensions are :
- <u>Width = 7 inches</u>
- Length = 2(7) + 9
- <u>Length = 23 inches</u>
Answer:
20 m by 10 m
Step-by-step explanation:
let w be width and l be length , then
2(l + w) = 60 ( divide both sides by 2 )
l + w = 30 ( subtract w from both sides )
l = 30 - w → (1)
lw = 200 → (2)
Substitute l = 30 - w into (2)
w(30 - w) = 200 ← distribute parenthesis on left side
30w - w² = 200 ( subtract 200 from both sides )
30w - w² - 200 = 0 ( multiply through by - 1 )
w² - 30w + 200 = 0 ← in standard form
(w - 10)(w - 20) = 0 ← in factored form
Equate each factor to zero and solve for w
w - 10 = 0 ⇒ w = 10
w - 20 = 0 ⇒ w = 20
Substitute these values into (1)
l = 30 - 10 = 20
l = 30 - 20 = 10
dimensions of field is 20 m by 10 m
6 4/5 + 6 4/5 + 2 2/3 + 2 2/3 = 18 14/15
