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11Alexandr11 [23.1K]
3 years ago
6

Jonh's collection contains 20 books including 2 historical novels if John randomly selects a book to read what is the probility

that it will be a historical novel write your answer as a fraction or whole number
Mathematics
1 answer:
Anarel [89]3 years ago
7 0

Answer:2/20 or 20%

Step-by-step explanation:

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In a semiconductor manufacturing process, three wafers from a lot are tested. Each wafer is classified as pass or fail. Assume t
Angelina_Jolie [31]

Answer:

P(X = 0) = 0.027

P(X = 1) = 0.189

P(X = 2) = 0.441

P(X = 3)= 0.343

Step-by-step explanation:

The probability mass function P(X = x) is the probability that X happens x times.

When n trials happen, for each x \leq n, the probability mass function is given by:

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

In which p is the probability that the event happens.

pe_{n,x}, is the permutation of n elements with x repetitions(when there are multiple events happening(like one passes and two not passing)). It can be calculated by the following formula:

pe_{n,x} = \frac{n!}{x!}

The sum of all P(X=x) must be 1.

In this problem

We have 3 trials, so n = 3

The probability that a wafer pass a test is 0.7, so p = 0.7

Determine the probability mass function of the number of wafers from a lot that pass the test.

P(X = 0) = (0.7)^{0}.(0.3)^{3} = 0.027

P(X = 1) = pe_{3,1}.(0.7).(0.3)^{2} = 0.189

P(X = 2) = pe_{3,2}.(0.7)^{2}.(0.3) = 0.441

P(X = 3) = (0.7)^{3} = 0.343

5 0
3 years ago
The Hamden board of education wants to know how the community feels about building a new media center for the middle school. The
Alex Ar [27]

Answer:

According to the statement above, The Hamden board of education called every tenth person on the registration list. So let's analyze each case:

The sample is not randomly chosen (FALSE)

Given that the statement doesn't tell us anything about the way they choose the sample, it is reasonable to conclude that this is a randomly chosen. They called every tenth person on the registration list until the number of people was 40.

The sample should be larger to give more reliable information (TRUE)

You did not have to use mathematics to determine that you would need more information to get a conclusion. You must increase the sample, that is, the sample must be larger to give a reliable information.

The sample size is too large to make inferences (False)

This is explained in the previous item. If the sample should be lager is because the size is not too large.

The sample size is too small to represent the population (TRUE

This is true because 40 voters represent barely 0.5% of the entire list. This list has 7300 voters, so getting the conclusion from this sample doesn't provide with a strong conclusion.

The sample size is too small and will show larger variation. (FALSE)

Although the sample size is too small, the sample size not necessarily will show variation. In fact, it is possible that it does not show any variation and most of the people feel well about building a new media center for the middle school but it doesn't mean that the whole community does.

The sample is invalid because it randomly chooses voters. (FALSE)

It is false because in probability studies the sample is chosen randomly, so you get conclusions about the whole population always taking samples that represent the population as a whole.

The sample size is too small and can lead to false inferences (TRUE)

You can get false conclusions given that the sample size is too small. It's important to note that the sample size supports the conclusion of the study, so the sample must increase to have a reliable study.

5 0
3 years ago
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Is it always true that multiplying a negative factor by a positive factor results in a negative? If yes, provide an example. If
Fed [463]

Answer:

yes because -3x4 would be negative 3 four times, reseulting in a negative number

Step-by-step explanation:

hope this helped

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2 years ago
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Which statement describes the relationship between kilometers and meters.
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Statement B describes the relationship
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Which collection of three side lengths will NOT form a triangle?
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Just multiply each line then whatever one doesnt have 180 as the answer choose it
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