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morpeh [17]
3 years ago
14

A student takes a true-false test that has 10 questions and guesses randomly at each answer. Let X be the number of questions an

swered correctly. Find P(Fewer than 3). Round your answer to 2 decimal places.
Mathematics
1 answer:
Dvinal [7]3 years ago
4 0

Answer:

P(Fewer than 3) = 0.05.

Step-by-step explanation:

We are given that a student takes a true-false test that has 10 questions and guesses randomly at each answer.

The above situation can be represented through Binomial distribution;

P(X=r) = \binom{n}{r}p^{r} (1-p)^{n-r} ; x = 0,1,2,3,.....

where, n = number of trials (samples) taken = 10 questions

            r = number of success = fewer than 3

           p = probability of success which in our question is probability

                that question is answered correctly, i.e; 50%

<u>LET X = Number of questions answered correctly</u>

So, it means X ~ Binom(n = 10, p = 0.50)

Now, Probability that Fewer than 3 questions are answered correctly is given by = P(X < 3)

P(X < 3)  = P(X = 0) + P(X = 1) + P(X = 2)

=  \binom{10}{0}\times 0.50^{0} \times (1-0.50)^{10-0}+ \binom{10}{1}\times 0.50^{1} \times (1-0.50)^{10-1}+ \binom{10}{2}\times 0.50^{2} \times (1-0.50)^{10-2}

=  1 \times 0.50^{10} + 10 \times 0.50^{10} +45 \times 0.50^{10}

=  0.05

Hence, the P(Fewer than 3) is 0.05.

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Answer:

-The slope:

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Step-by-step explanation:

-To find the slope, you need this trick:

m= \frac{rise}{run}

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Rise: 3

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3 years ago
Which construction would you use to construct a right triangle with a compass and a straightedge?
polet [3.4K]
A I think would be the correct answer

5 0
3 years ago
-4(w+1)=-24 solve for w
sineoko [7]

Answer:

w = 5

Step-by-step explanation:

Step 1: Simplify both sides of the equation.

−4(w+1)=−24

(−4)(w)+(−4)(1)=−24(Distribute)

−4w+−4=−24

−4w−4=−24

Step 2: Add 4 to both sides.

−4w−4+4=−24+4

−4w=−20

Step 3: Divide both sides by -4.

-4w/-4 = -20/-4

w=5

<em>Hope this helped and plz mark as brainliest!</em>

<em></em>

<em>Luna G.</em>

8 0
3 years ago
The rules of a game allow a team to score either 2 points or 5 points, depending on the nature of the scoring play. If the final
umka2103 [35]

Answer:

9

Step-by-step explanation:

Given that :

Total Number of scorings (both Teams) = 18

Let :

x = number of 5 point score ; y = number of 2 point score

Total points scored = 34 + 29 = 63

x + y = 18 - - - (1)

5x + 2y = 63 - - (2)

From (1)

y = 18 - x

In (2) ; we have ;

5x + 2(18 - x) = 63

5x + 36 - 2x = 63

3x + 36 = 63

3x = 63 - 36

3x = 27

x = 9

9 5-point plays

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3 years ago
If a = 31, what is the circumference of the circle? (Round to one decimal place.)
gregori [183]

circumference is 62pi which equals 194.8

area is 31^2pi which equals 3109.1

3 0
2 years ago
Read 2 more answers
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