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3 years ago

9

PLEASE HELP :((( When a number x is multiplied by 4 and the result is 2/5

1 answer:

ioda3 years ago

4 0

I don't understand the question

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Which pair of undefined terms is used to define a ray

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Whats the options please?

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3 years ago

A multiple-choice examination has 15 questions, each with five answers, only one of which is correct. Suppose that one of the st

Alex

Answer:

0.0111% probability that he answers at least 10 questions correctly

Step-by-step explanation:

For each question, there are only two outcomes. Either it is answered correctly, or it is not. The probability of a question being answered correctly is independent from other questions. So we use the binomial probability distribution to solve this question.

Binomial probability distribution

The binomial probability is the probability of exactly x successes on n repeated trials, and X can only have two outcomes.

$P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}$

In which $C_{n,x}$ is the number of different combinations of x objects from a set of n elements, given by the following formula.

$C_{n,x} = \frac{n!}{x!(n-x)!}$

And p is the probability of X happening.

A multiple-choice examination has 15 questions, each with five answers, only one of which is correct.

This means that $n = 15, p = \frac{1}{5} = 0.2$

What is the probability that he answers at least 10 questions correctly?

$P(X \geq 10) = P(X = 10) + P(X = 11) + P(X = 12) + P(X = 13) + P(X = 14) + P(X = 15)$

$P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}$

$P(X = 10) = C_{15,10}.(0.2)^{10}.(0.8)^{5} = 0.0001$

$P(X = 11) = C_{15,11}.(0.2)^{11}.(0.8)^{4} = 0.000011$

$P(X = 12) = C_{15,12}.(0.2)^{12}.(0.8)^{3} \cong 0$

$P(X = 13) = C_{15,13}.(0.2)^{13}.(0.8)^{2} \cong 0$

$P(X = 14) = C_{15,14}.(0.2)^{14}.(0.8)^{1} \cong 0$

$P(X = 15) = C_{15,15}.(0.2)^{15}.(0.8)^{0} \cong 0$

$P(X \geq 10) = P(X = 10) + P(X = 11) + P(X = 12) + P(X = 13) + P(X = 14) + P(X = 15) = 0.0001 + 0.000011 = 0.000111$

0.0111% probability that he answers at least 10 questions correctly

3 0

3 years ago

Dividing a Fraction into Equal Groups

Sergeu [11.5K]

Answer:

Each hiker carried the backpack for 1/5 of the total trail distance

Step-by-step explanation:

Three members of a teen hiking group hiked 3/5 of the entire Appalachian trail, each teen carried the backpack the same distance

=> each teen carried the backpack for = (1/3) (3/5) of total Distance = 1/5

3 0

2 years ago

Please help it is due in 10 minutes

Otrada [13]

Answer:

1. X= 4

2. X= 1

3. X= 3

4. X= 5

5. X= 7

6. X= -3/4

7. X= 6

8. X= 5

Step-by-step explanation:

5 0

3 years ago

Read 2 more answers

Pls answer my last one to Rodney sold 45,612 copies of his book and Beth sold 45,612 x one half copies of her book. Which statem

Elden [556K]

Answer:

its most likely b

hope this helps!

6 0

3 years ago