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3 years ago

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Each question on a multiple-choice exam has four choices. One of the choices is correct, worth four points. Another choice is wr

ong but carries partial credit of one point. The other two choices are wrong and worth negative one point. If a student picks answers at random, what is the expected value of his or her score for a problem?
A 0.75
B 0.25
C 1.25
D 1.50

1 answer:

kifflom [539]3 years ago

8 0

Answer:A)0.75

Step-by-step explanation:

Given

There are four options to a question

out of which one is correct with 4 points

one is wrong but carries 1 point

Other two are wrong with a negative Point

Probability of selecting an option is $\frac{1}{4}$

Expected score $=\frac{1}{4}\times 4+\frac{1}{4}\times 1+\frac{1}{4}\times (-1)+\frac{1}{4}\times (-1)$

Expected score=1+0.25-0.5

Expected score=0.75

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add the term that makes the given expression into a perfect square. write the result as the square of a bracketed expression c s

Molodets [167]

<h2>Perfect Squares</h2>

Perfect square formula/rules:

$a^2+2ab+b^2=(a+b)^2$
$a^2-2ab+b^2=(a-b)^2$

Trinomials are often organized like $ax^2+bx+c$ .

The <em>b</em> value in this case is <em>c</em>, and it will always equal the square of half of the <em>b</em> value.

Perfect square trinomial: $ax^2+bx+(\dfrac{b}{2})^2$
or $ax^2-bx+(\dfrac{b}{2})^2$

<h2>Solving the Question</h2>

We're given:

$c^2-4c$

In a trinomial, we're given the $ax^2$ and $bx$ values. <em>a</em> in this case is 1 and <em>b</em> in this case is 4. To find the third value by dividing 4 by 2 and squaring the quotient:

4 ÷ 2 = 2
2² = 4

Therefore, the term that we can add is + 4.

$c^2-4c+4$

To write this as the square of a bracketed expression, we can follow the rule $a^2-2ab+b^2=(a-b)^2$ :

$(c-2)^2$

<h2>Answer</h2>

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2 years ago

Does each equation represent exponential decay or exponential growth?

lisov135 [29]

Answer:

1. $H = 5.9(0.82)^{t}$ . Exponential decay function.

2. $y = 0.8(3.6)^{t}$ . Exponential growth function.

3. $f(t) = 0.72(15)^{t}$ . Exponential growth function.

4. $A = \frac{4}{9} (8)^{t}$ . Exponential growth function.

5. $A = (\frac{4}{3})^{t}$ . Exponential growth function.

6. $H = \frac{7}{2} (\frac{5}{6} )^{t}$ . Exponential decay function.

7. g(x) = 0.3(x). Not an exponential function.

Step-by-step explanation:

1. $H = 5.9(0.82)^{t}$ . This is an exponential decay function.

As the value of t increases H-value decreases.

2. $y = 0.8(3.6)^{t}$ . This is an exponential function of growth.

As the value of t increases y-value also increases.

3. $f(t) = 0.72(15)^{t}$ . This is an another example of exponential growth function.

As the value of t increases f(t)-value also increases.

4. $A = \frac{4}{9} (8)^{t}$ . This is again an example of exponential growth function.

As the value of t increases A-value also increases.

5. $A = (\frac{4}{3})^{t}$ . This is again an example of exponential growth function.

As the value of t increases A-value also increases.

6. $H = \frac{7}{2} (\frac{5}{6} )^{t}$ . This is another an example of exponential decay function.

As the value of t increases, H-value decreases.

7. g(x) = 0.3(x). This is a non-exponential function. (Answer)

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3 years ago

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Korolek [52]

Answer:

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Step-by-step explanation:

$f(x)=-\frac{2}{3x}+3$

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b) $f(x)=-5$

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3 years ago

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Answer:

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Step-by-step explanation:

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<u>To calculate the future value (FV), we need to use the following formula:</u>

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FV= $3,725.07

3 0

3 years ago

Please help! I really don't understand!

Varvara68 [4.7K]

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3 years ago