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4 years ago

8

Solve for X 1/2(x-2)+1/3(x-3)+1/4(x-4)=10

1 answer:

Lisa [10]4 years ago

6 0

X=12
Just distribute and solve :)
Work shown below:

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Marta Perez sells coffee beans to local coffee shops. She earns a 10% straight commission on all sales. In November, her sales t

ruslelena [56]

The answer is $3,850 and have a very nice day

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3 years ago

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

Readme [11.4K]

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

3 years ago

Write this polynomial in standard form- (5a+2)(a+4)

ikadub [295]

Answer:

5a²+22a+8

Step-by-step explanation:

(5a+2)(a+4)

5a² + 20a + 2a + 8

5a² + 22a + 8

7 0

3 years ago

Read 2 more answers

Which addition does this model represent.

Elina [12.6K]

It represents the first one 3+(-1)

5 0

2 years ago

University Theater sold 465 tickets for a play. Tickets cost $23 per adult and $13 per senior citizen. If total receipts were $7

liq [111]

<u>Answer:</u>

355 senior citizen tickets were sold.

<u>Step-by-step explanation:</u>

Assuming a to the the ticket of adults and s to be the ticket of senior citizens, we can write two equations as:

$a +s=465$ --- (1)

$23a+13s=7145$ --- (2)

From equation 1, $a=465-s$ .

Substitute $a$ in equation 2 to get:

$23 (465-s) + 13s = 7145$

$10695 - 23s +13s =7145$

$-10s = -3550$

$s = 355$

Therefore, there were 355 senior citizen tickets sold.

8 0

3 years ago