What is the edge length of 216 cubic inches?

A student takes an exam containing 1414 multiple choice questions. The probability of choosing a correct answer by knowledgeable

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Answer:

0.0082 = 0.82% probability that he will pass

Step-by-step explanation:

For each question, there are only two possible outcomes. Either the students guesses the correct answer, or he guesses the wrong answer. The probability of guessing the correct answer for a question is independent of 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.

In this problem we have that:

$n = 14, p = 0.3$ .

If the student makes knowledgeable guesses, what is the probability that he will pass?

He needs to guess at least 9 answers correctly. So

$P(X \geq 9) = P(X = 9) + P(X = 10) + P(X = 11) + P(X = 12) + P(X = 13) + P(X = 14)$

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

$P(X = 9) = C_{14,9}.(0.3)^{9}.(0.7)^{5} = 0.0066$

$P(X = 10) = C_{14,10}.(0.3)^{10}.(0.7)^{4} = 0.0014$

$P(X = 11) = C_{14,11}.(0.3)^{11}.(0.7)^{3} = 0.0002$

$P(X = 12) = C_{14,12}.(0.3)^{12}.(0.7)^{2} = 0.000024$

$P(X = 13) = C_{14,13}.(0.3)^{13}.(0.7)^{1} = 0.000002$

$P(X = 14) = C_{14,14}.(0.3)^{14}.(0.7)^{0} \cong 0$

$P(X \geq 9) = P(X = 9) + P(X = 10) + P(X = 11) + P(X = 12) + P(X = 13) + P(X = 14) = 0.0066 + 0.0014 + 0.0002 + 0.000024 + 0.000002 = 0.0082$

0.0082 = 0.82% probability that he will pass

6 0

2 years ago

Garrett and Carter went to the movies last weekend. Together they bought 2 drinks and 2 popcorns. They spent a total of $12.50.

-BARSIC- [3]

The cost of one drink is $2.50 and cost of one popcorn is $3.75

<u><em>Explanation</em></u>

Suppose, the cost of one drink is $x$ dollar and cost of one popcorn is $y$ dollar.

Given that, total cost for 2 drinks and 2 popcorns is $12.50 and total cost for 6 drinks and 5 popcorns is $33.75

So, the system of equations will be......

$2x+2y=12.50 ..................................... (1)\\ \\ 6x+5y= 33.75 ..................................... (2)$

Multiplying equation (1) by -3 , we will get.....

$-3(2x+2y)=-3(12.50)\\ \\ -6x-6y=-37.50 ..................................... (3)$

Now, adding equation (2) and equation (3) , we will get ............

$5y-6y=33.75-37.50\\ \\ -y=-3.75\\ \\ y=3.75$

Plugging this $y=3.75$ into equation (1) ......

$2x+2(3.75)=12.50\\ \\ 2x+7.50=12.50\\ \\ 2x=12.50-7.50=5\\ \\ x=\frac{5}{2}=2.50$

So, the cost of one drink is $2.50 and cost of one popcorn is $3.75

6 0

3 years ago

the populatipn of a school of fish increases at a rate of 18% a Month. There are currently 500 fish in the school.

ruslelena [56]

You first must find the 18% of the fish population.

You multiply 500 by .18 . You are supposed to get 90.

90 is the 18% fish increase.

Then you just add 500 + 90 and you will get 590 fish that are now in the school.

8 0

3 years ago

8.4×0.5 showing work

Katen [24]

Can u add a picture?

8 0

2 years ago

Maria uses 1 1/2 cups of milk for her cereal and

jonny [76]

Answer:

more, she uses 17.5 cups a week

Step-by-step explanation: