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3 years ago

A test has 20 questions. If peter gets 80% correct, how many questions did peter missed?

Mathematics

2 answers:

Umnica [9.8K]3 years ago

8 0

16 because if you put 16 into a percentage it's 80. 16 divide 20 times 100 equal 80

denpristay [2]3 years ago

3 0

20 question and gets 80% correct answers.

therefore, 100% - 80% = 20% wrong answers.

20%*20questions = 0.2*20 = 4 questions

there are 4 questions that peter missed

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Determine whether each equation below does or does not represent a proportional relationship. support your answer using either a

Triss [41]

Answer:

As the ratio for all the points on the equation y = x is same. Hence, the equation y = x REPRESENTS a proportional relationship.
As the ratio for all the points on the equation y = x+2 is not same. Hence, the equation y = x + 2 DOES NOT REPRESENT a proportional relationship.

Step-by-step explanation:

Solving equation A: y = x 

Let us consider the given equation A:

y = x

Putting x = 1 in y = x

y = x

y = 1 ∵ x = 1

Hence, (1, 1) is the ordered pair of y = x

Putting x = 2 in y = x

y = x

y = 2 ∵ x = 2

Hence, (2, 2) is the ordered pair of y = x

Putting x = 3 in y = x

y = x

y = 3 ∵ x = 3

Hence, (3, 3) is the ordered pair of y = x

Putting x = 4 in y = x

y = x

y = 4 ∵ x = 4

Hence, (4, 4) is the ordered pair of y = x

Putting x = 5 in y = x

y = x

y = 5 ∵ x = 5

Hence, (5, 5) is the ordered pair of y = x

Lets us consider all the ordered pairs i.e. (1, 1), (2, 2), (3, 3), (4, 4) and (5, 5) to make a table for y = x.

y x

1 1

2 2

3 3

4 4

5 5

As from the table, lets take the ratio of every point i.e. y/x

For (1, 1), the ratio will be y/x ⇒ 1/1 = 1
For (2, 2), the ratio will be y/x ⇒ 2/2 = 1
For (3, 3), the ratio will be y/x ⇒ 3/3 = 1
For (4, 4), the ratio will be y/x ⇒ 4/4 = 1
For (5, 5), the ratio will be y/x ⇒ 5/5 = 1

Hence, the ratio for all the points on the equation y = x is same. Hence, the equation y = x REPRESENTS a proportional relationship. Please also check the graph in attached figure a.

Solving equation A: y = x +2

Let us consider the given equation A:

y = x + 2

Putting x = 1 in y = x + 2

y = x + 2

y = 1 + 2 ⇒ 3 ∵ x = 1

Hence, (1, 3) is the ordered pair of y = x + 2

Putting x = 2 in y = x + 2

y = x + 2

y = 2 +2 ⇒ 4 ∵ x = 2

Hence, (2, 4) is the ordered pair of y = x + 2

Putting x = 3 in y = x + 2

y = x + 2

y = 3 + 2 ⇒ 5 ∵ x = 3

Hence, (3, 5) is the ordered pair of y = x + 2

Putting x = 4 in y = x + 2

y = x + 2

y = 4 + 2 ⇒ 6 ∵ x = 4

Hence, (4, 6) is the ordered pair of y = x + 2

Putting x = 5 in y = x + 2

y = x + 2

y = 5 +2 ⇒ 7 ∵ x = 5

Hence, (5, 7) is the ordered pair of y = x + 2

Lets us consider all the ordered pairs i.e. (1, 3), (2, 4), (3, 5), (4, 6) and (5, 7) to make a table for y = x + 2.

y x + 2

1 3

2 4

3 5

4 6

5 7

As from the table, lets take the ratio of every point i.e. y/x

For (1, 3), the ratio will be y/x ⇒ 3/1 = 3
For (2, 4), the ratio will be y/x ⇒ 4/2 = 2
For (3, 5), the ratio will be y/x ⇒ 5/3 = 5/3
For (4, 6), the ratio will be y/x ⇒ 6/4 = 3/2
For (5, 7), the ratio will be y/x ⇒ 7/5 = 7/5

Hence, the ratio for all the points on the equation y = x+2 is not same. Hence, the equation y = x + 2 DOES NOT REPRESENT a proportional relationship. Please also check the graph in attached figure a.

Keywords: equation, graph

Learn more equation and graphs from brainly.com/question/12767017

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6 0

3 years ago

PLZ HELP AHHHH I NEED HELPEPWOEOW

Nat2105 [25]

Answer:

ops sorry thx for the free points

Step-by-step explanation:

5 0

3 years ago

The lengths of nails produced in a factory are normally distributed with a mean of 3.34 centimeters and a standard deviation of

Shtirlitz [24]

Answer:

3.47 and 3.21

Step-by-step explanation:

Let us assume the nails length be X

$X \sim N(3.34,0.07^2)$

Value let separated the top 3% is T and for bottom it would be B

$P(X < T)= 0.97$

Now converting, we get

$P(Z < \frac{T-3.34}{0.07})= 0.97$

Based on the normal standard tables, we get

$P(Z < 1.881)= 0.97$

Now compare these two above equations

$\frac{T-3.34}{0.07} = 1.881 \\\\ T = 1.881 \times 0.07 + 3.34 \\\\ = 3.47$

So for top 3% it is 3.47

Now for bottom we applied the same method as shown above

$P(Z < \frac{B-3.34}{0.07})= 0.03$

Based on the normal standard tables, we get

$P(Z < -1.881)= 0.03$

Now compare these two above equations

$\frac{B-3.34}{0.07} = -1.881$

$= -1.881 \times 0.07 + 3.34 \\\\ = 3.21$

hence, for bottom it would be 3.21

7 0

3 years ago

On a special right triangle if the sides are 6 and 6 then what is the hypothinus

Black_prince [1.1K]

We are talking about a right triangle so the phytagoras equation can be used:
$a^{2} + b^{2} = c^{2}$
$6^{2} + 6^{2} = 36 + 36 = 72 = c^{2}$
$\sqrt{ c^{2} } = \sqrt{72} =8.48528...$
So the hypothinus is equal to approximately 8.49

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3 years ago

Half of a class took Form A of a test, and half took Form B. Of the students who took Form B, 39% passed. What is the probabilit

Gnom [1K]

Answer: the answer would be 0.305

7 0

3 years ago