I) the probability that the person is female is 8.33%.
II) the probability that the person has a risk factor heterosexual contact is 6.40%.
III) the probability that the person is female or has a risk factor of IV drug user is 23.47%.
IV) the probability that the person is female and has a risk factor of homosexual is 0%.
V) the probability that the person is male and has a risk factor of IV drug user is 15.13%.
VI) the probability that the person is female given that the person got the disease from heterosexual contact is 69.38%.

Given the data mentioned in the table, the following calculations must be performed to obtain the requested probabilities:

I.-

(0 + 70 + 136 + 49) / (2,146 + 463 + 60 + 135 + 0 + 70 + 136 + 49) = X

255/3059 = X

0.0833 = X

II.-

196/3059 = X

0.0640 = X

III.-

(255 + 463) / 3059 = X

718/3059 = X

0.2347 = X

IV.-

0/3059 = X

0 = X

V.-

463/3059 = X

0.1513 = X

VI.-

136/196 = X

0.6938 = X

Therefore, I) the probability that the person is female is 8.33%, II) the probability that the person has a risk factor heterosexual contact is 6.40%, III) the probability that the person is female or has a risk factor of IV drug user is 23.47%, IV) the probability that the person is female and has a risk factor of homosexual is 0%, V) the probability that the person is male and has a risk factor of IV drug user is 15.13%, and VI) the probability that the person is female given that the person got the disease from heterosexual contact is 69.38%.

Learn more about maths in brainly.com/question/25815188

3 0

2 years ago

Determine whether the integral converges.

Kryger [21]

You have one mistake which occurs when you integrate $\dfrac1{1-p^2}$ . The antiderivative of this is not in terms of $\tan^{-1}p$ . Instead, letting $p=\sin r$ (or $\cos r$ , if you want to bother with more signs) gives $\mathrm dp=\cos r\,\mathrm dr$ , making the indefinite integral equality

$\displaystyle-\frac12\int\frac{\mathrm dp}{1-p^2}=-\frac12\int\frac{\cos r}{1-\sin^2r}\,\mathrm dr=-\frac12\int\sec r\,\mathrm dr=\ln|\sec r+\tan r|+C$

and then compute the definite integral from there.

$-\dfrac12\ln|\sec r+\tan r|\stackrel{r=\sin^{-1}p}=-\dfrac12\ln\left|\dfrac{1+p}{\sqrt{1-p^2}}=\ln\left|\sqrt{\dfrac{1+p}{1-p}}\right|$
$\stackrel{p=u/2}=-\dfrac12\ln\left|\sqrt{\dfrac{1+\frac u2}{1-\frac u2}}\right|=-\dfrac12\ln\left|\sqrt{\dfrac{2+u}{2-u}}\right|$
$\stackrel{u=x+1}=-\dfrac12\ln\left|\sqrt{\dfrac{3+x}{1-x}}\right|$
$\implies-\dfrac12\displaystyle\lim_{t\to\infty}\ln\left|\sqrt{\dfrac{3+x}{1-x}}\right|\bigg|_{x=2}^{x=t}=-\frac12\left(\ln|-1|-\ln\left|\sqrt{\frac5{-1}}\right|\right)=\dfrac{\ln\sqrt5}2=\dfrac{\ln5}4$

Or, starting from the beginning, you could also have found it slightly more convenient to combine the substitutions in one fell swoop by letting $x+1=2\sec y$ . Then $\mathrm dx=2\sec y\tan y\,\mathrm dy$ , and the integral becomes

$\displaystyle\int_2^\infty\frac{\mathrm dx}{(x+1)^2-4}=\int_{\sec^{-1}(3/2)}^{\pi/2}\frac{2\sec y\tan y}{4\sec^2y-4}\,\mathrm dy$
$\displaystyle=\frac12\int_{\sec^{-1}(3/2)}^{\pi/2}\csc y\,\mathrm dy$
$\displaystyle=-\frac12\ln|\csc y+\cot y|\bigg|_{y=\sec^{-1}(3/2}}^{y=\pi/2}$
$\displaystyle=-\frac12\lim_{t\to\pi/2^-}\ln|\csc y+\cot y|\bigg|_{y=\sec^{-1}(3/2)}^{y=t}$
$\displaystyle=-\frac12\left(\lim_{t\to\pi/2^-}\ln|\csc t+\cot t|-\ln\frac5{\sqrt5}\right)$
$=\dfrac{\ln\sqrt5}2-\dfrac{\ln|1|}2$
$=\dfrac{\ln5}4$

Another way to do this is to notice that the integrand's denominator can be factorized.

$x^2+2x-3=(x+3)(x-1)$

So,

$\dfrac1{x^2+2x-3}=\dfrac1{(x+3)(x-1)}=\dfrac14\left(\dfrac1{x-1}-\dfrac1{x+3}\right)$

There are no discontinuities to worry about since you're integrate over $[2,\infty)$ , so you can proceed with integrating straightaway.

$\displaystyle\int_2^\infty\frac{\mathrm dx}{x^2+2x-3}=\frac14\lim_{t\to\infty}\int_2^t\left(\frac1{x-1}-\frac1{x+3}\right)\,\mathrm dx$
$=\displaystyle\frac14\lim_{t\to\infty}(\ln|x-1|-\ln|x+3|)\bigg|_{x=2}^{x=t}$
$=\displaystyle\frac14\lim_{t\to\infty}\ln\left|\frac{x-1}{x+3}\right|\bigg|_{x=2}^{x=t}$
$=\displaystyle\frac14\left(\lim_{t\to\infty}\ln\left|\frac{t-1}{t+3}\right|-\ln\frac15\right)$
$=\displaystyle\frac14\left(\ln1-\ln\frac15\right)$
$=-\dfrac14\ln\dfrac15=\dfrac{\ln5}4$

Just goes to show there's often more than one way to skin a cat...

7 0

2 years ago

50. If angles are complementary, what’s value of x?

maks197457 [2]

Answer:

x = 14

Step-by-step explanation:

For complementary angles, the sum of two angles is equal to 90 degrees.

We have,

$m\angle ABC = 4x-10\\\\m\angle DBC = x+30$

ATQ,

$4x-10+x+30=90$

Taking like terms together,

4x+x =90-30+10

5x = 70

x = 14

So, the value of x is 14.

6 0

2 years ago