Anyone ? please help:') (middle school)

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

i need help please! I think I know the answer but for some reason my brain's telling me that it's wrong so if someone could expl

Ivenika [448]

Considering the slopes of the segments, the correct option is:

D. No, because the triangle ABC doesn't have a pair of perpendicular sides.

<h3>When are lines parallel, perpendicular or neither?</h3>

The slope, given by change in y divided by change in x, determines if the lines are parallel, perpendicular, or neither, as follows:

If they are equal, the lines are parallel.

If their multiplication is of -1, they are perpendicular.

Otherwise, they are neither.

Here, we have to find if there are perpendicular segments, that is, if two slopes multiplied have a value of -1, then:

mAB = (-7 - 9)/(11 - 1) = -8/5.

mAC = (3 - 9)/(-9 - 1) = 3/5.

mBC = (3 - (-7))/(-9 - 11) = -1/2.

No sides are perpendicular, hence option D is correct.

More can be learned about slopes at brainly.com/question/20847660

#SPJ1

6 0

2 years ago

1. Charlene makes $10 per hour babysitting and $5 per hour gardening. This week, she wants to make at least $80.

Lady_Fox [76]

Answer:

Step-by-step explanation:

Well is she wanted to make $80 “b” she would have to garden for 16 hours to make a maximum of $80

“C” if she wanted to make it out of babysitting she would have to work the same for 8 hours if she babysit

Workout : b part = 10+10+10+10+10+10+10+10 Key:10=2

:c part = 20+20+20+20. Key:20=2

Sorry I didn’t do a but just add all the things above and u get your answer

4 0

3 years ago

1) Find the slope and the y-byintercept of the line that passes through the points (1,5) and (3,9)

dimulka [17.4K]

Answer: slope= 2, y-intercept= 3

4 0

3 years ago

Ronald bikes 6.9 miles each day how far has ronald biked in seven days

kifflom [539]

Well, first you have to do 6.9 times the number of days, which is 7, and you will find the answer
6.9 x 7 = 48.2

7 0

3 years ago

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Anyone ?please help:') (middle school)