8=p/7 what does P equal

A common blood test performed on pregnant women to screen for chromosome abnormalities in the fetus measures the human chorionic

goldfiish [28.3K]

Answer:

(a) The proportion of women who are tested, get a negative test result is 0.82.

(b) The proportion of women who get a positive test result are actually carrying a fetus with a chromosome abnormality is 0.20.

Step-by-step explanation:

The Bayes' theorem states that the conditional probability of an event E $_{i}$ , of the sample space S, given that another event A has already occurred is:

$P(E_{i}|A)=\frac{P(A|E_{i})P(E_{i})}{\sum\liits^{n}_{i=1}{P(A|E_{i})P(E_{i})}}$

The law of total probability states that, if events E₁, E₂, E₃... are parts of a sample space then for any event A,

$P(A)=\sum\limits^{n}_{i=1}{P(A|B_{i})P(B_{i})}$

Denote the events as follows:

X = fetus have a chromosome abnormality.

Y = the test is positive

The information provided is:

$P(X)=0.04\\P(Y|X)=0.90\\P(Y^{c}|X^{c})=0.85$

Using the above the probabilities compute the remaining values as follows:

$P(X^{c})=1-P(X)=1-0.04=0.96$

$P(Y^{c}|X)=1-P(Y|X)=1-0.90=0.10$

$P(Y|X^{c})=1-P(Y^{c}|X^{c})=1-0.85=0.15$

(a)

Compute the probability of women who are tested negative as follows:

Use the law of total probability:

$P(Y^{c})=P(Y^{c}|X)P(X)+P(Y^{c}|X^{c})P(X^{c})$

$=(0.10\times 0.04)+(0.85\times 0.96)\\=0.004+0.816\\=0.82$

Thus, the proportion of women who are tested, get a negative test result is 0.82.

(b)

Compute the value of P (X|Y) as follows:

Use the Bayes' theorem:

$P(X|Y)=\frac{P(Y|X)P(X)}{P(Y|X)P(X)+P(Y|X^{c})P(X^{c})}$

$=\frac{(0.90\times 0.04)}{(0.90\times 0.04)+(0.15\times 0.96)}$

$=0.20$

Thus, the proportion of women who get a positive test result are actually carrying a fetus with a chromosome abnormality is 0.20.

6 0

3 years ago

What is the difference for 43-17?

Zolol [24]

The answer is 26 hope that helped

4 0

3 years ago

Read 2 more answers

Evaluate the variable expression when a = 5, b = 5, and c = -4. Bc divided by (2a)

zlopas [31]

Answer:

-2

Step-by-step explanation:

Bc÷2a

5×-4÷2×5

-20÷10

-2

6 0

3 years ago

Read 2 more answers

A set of a thousand numbers has a mean of zero.

Alona [7]

We want to find the mean of two elements in a set, given that we know the other elements of the set and the mean of the whole set.

The answer is: -490

-----------------------------

For a set with N elements {x₁, x₂, ..., xₙ} the mean is given by:

$M = \frac{x_1 + x_2 + ... + x_n}{N}$

Here we know that:

The mean of the set is 0.
The set has 1000 elements.
998 of these elements are ones, the other two are A and B.

We want to find the mean of the values of A and B.

First, we can start by writing the equation for the mean:

$\frac{1 + 1 + 1 + ... A + B}{1000} = 0$

We can rewrite this as:

$1 + 1 + 1 +... + A + B = 0$

And we have 998 ones, then:

$1 + 1 + 1 +... + A + B = 998 + A + B = 0\\\\B = - 998 - A$

Now we have B isolated.

With this, the mean of A and B can be written as:

$\frac{A + B}{2} = \frac{A - 980 - A}{2} = -490$

So we can conclude that the mean of the other two numbers is -490.

If you want to learn more, you can read:

brainly.com/question/22871228

5 0

2 years ago

Out of 250 coins, 50 are in mint condition. What is the ratio of mint condition coins to the total number of coins?

dimulka [17.4K]

Answer:

$1 : 5$

Step-by-step explanation:

Given:

Mint condition coins = $50$

Total number of coins = $250$

Ratio

The questions asks for the ratio between mint condition coins to the total number of coins, so:

Mint condition coins : number of coins = $50:250$

$= 1:5$ (simplified form)

Hope this helps :)

7 0

3 years ago

8=p/7 what does P equal￼￼

8=p/7 what does P equal