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3 years ago

What must be true for P (A and B) = P(A) x P(B)?

1 answer:

4 0

Answer: Choice C) A and B must be independent

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In general,
P(A and B) = P(A)*P(B|A)
and
P(A and B) = P(B)*P(A|B)

The only time P(A) = P(A|B) and P(B) = P(B|A) are true is when A and B are independent. In other words, one event occurring does not alter the probability of the other event.

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A woman is randomly selected from the 18–24 age group. For women of this group, systolic blood pressures (in mm Hg) are normally

Naddik [55]

Answer:

$X \sim N(114.8,13.1)$

Where $\mu=114.8$ and $\sigma=13.1$

We are interested on this probability

$P(X>140)$

And the best way to solve this problem is using the normal standard distribution and the z score given by:

$z=\frac{x-\mu}{\sigma}$

If we apply this formula to our probability we got this:

And we can find this probability using the complement rule:

$P(z>1.924)=1-P(z$

Step-by-step explanation:

Previous concepts

Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".

The Z-score is "a numerical measurement used in statistics of a value's relationship to the mean (average) of a group of values, measured in terms of standard deviations from the mean".

Solution to the problem

Let X the random variable that represent the variable of interest of a population, and for this case we know the distribution for X is given by:

$X \sim N(114.8,13.1)$

Where $\mu=114.8$ and $\sigma=13.1$

We are interested on this probability

$P(X>140)$

And the best way to solve this problem is using the normal standard distribution and the z score given by:

$z=\frac{x-\mu}{\sigma}$

If we apply this formula to our probability we got this: $P(X>140)=P(\frac{X-\mu}{\sigma}>\frac{140-\mu}{\sigma})=P(Z>\frac{140- 1114.8}{2.6})=P(z>1.924)$ And we can find this probability using the complement rule:

$P(z>1.924)=1-P(z$

8 0

4 years ago

Ax+by=c solving for y

german

Answer:

$ax + by = c \\ by = c - ax \\ \\ y = \frac{c - ax}{b} \\ \\ y = \frac{c}{b} - \frac{ax}{b}$

I hope I helped you^_^

8 0

3 years ago

Read 2 more answers

Complete the statements for the graph of f(x)=|x|.

Cerrena [4.2K]

below

Step-by-step explanation:

all real numbers

[0,∞]

increasing

decreasing

4 0

3 years ago

Which one of these graphs does not illustrate a function? And why

Svetach [21]

Answer:

It would be <em>Graph D</em>

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Step-by-step explanation:

It's graph D because according to the graph, it looks like the domain has 2 ranges since it made a vertical line. And as we know, vertical lines are not considered to be functional since a domain can't have more than one range.

3 0

3 years ago

Read 2 more answers

Which of the binomials below is a factor of this trinominal x^2-10x-39

Ksenya-84 [330]

Answer:

Step-by-step explanation:

To factorise the quadratic

Consider the factors of the constant term (- 39) which sum to give the coefficient of the x- term (- 10)

The factors are - 13 and + 3, since

- 13 × 3 = - 39 and - 13 + 3 = - 10, hence

x² - 10x - 39 = (x - 13)(x + 3) ← in factored form

x - 13 is a factor → C

4 0

3 years ago