-2y -3y + 8 = 8 -5y -12 solve for Y

A couple plans to have children until they get a girl, but they agree they will not have more than three children, even if all

barxatty [35]

Answer:

a)Let X be number of children

X=1,2,3

P(X=1)= 0.47

P(X=2) = 0.2491

P(X=3) = 0.942923

b) 3.7970

c) 1.6232

Step-by-step explanation:

The complete question is:

A couple plans to have children until they get a girl, but they agree they will not have more than three children, even if all are boys. Assume that the probability of having a girl is 47.00%.

a) Create a probability model for the number of children they'll have.

X=1,2,3

P(X=1)=??

P(X=2)= ??

P(X=30=???

(Round to four decimal places as needed

b) Find the expected number of children.

E(X)= ???

c) Find the expected number of boys they'll have.

Expected number of boys= ???

Solution:

Probability of a girl= 0.47

Probability of a boy= 0.53

a) P(X=1)= 0.47

P(X=2) = 0.47× 0.53= 0.2491

P(X=3)= 0.47× 0.53× 0.53 + 0.53× 0.53× 0.53

= 0.942923

b) E(number of children)= 1× P(X=1) + 2 ×P(X=2) + 3 × (PX=3)

= 3.796969

c) Y: number of boys

P(Y=1)= 0.53×0.47= 0.2491

P(Y=2) = 0.53×0.53×0.47=0.46375

P(Y=3)= 0.53× 0.53× 0.53= 0.148875

E(Y)= P(Y=1)×1 + P(Y=2)×2 + P(Y=3)×3

= 0.148875×3 +0.46375×2+0.2491 ×1

= 1.6232

5 0

3 years ago

I=prt(interest=principal.rate.time) solve for p

Black_prince [1.1K]

I = PRT/100
100I = PRT
P= 100I÷RT
P = 100I/RT

7 0

4 years ago

Read 2 more answers

(a) Find an angle between 0° and 360° that is coterminal with – 120°.

Novay_Z [31]

Answer:

a) $240\degree$

b) $\frac{15\pi}{4}$

Step-by-step explanation:

<u>Coterminal angles</u> have the same terminal sides in standard position.

a) To find an angle between $0\degree$ and $360\degree$ , that is coterminal with $-120\degree$ , we keep adding multiples of $360\degree$ until we get an angle within the specified range.

$-120\degree \implies -120\degree +360\degree=240\degree$ .

In some cases you would have to subtract in order to get the specified angle. That is when the angle given is positive.

b) This time we want to find an that coterminal with $\frac{15\pi}{4}$ radians.

We keep subtracting multiples of $2\pi$ until we get an angle measure within the specified range.

$\frac{15\pi}{4}=\frac{15\pi}{4}-2\pi=\frac{7\pi}{4}$

4 0

3 years ago

Evaluate 35/a when a=7. The value is

mestny [16]

Answer:

a = 5

Step-by-step explanation:

a = 7

35/a

35/(7)

= 5

Hope this helped

6 0

3 years ago

The lengths of text messages are normally distributed with a population standard deviation of 4 characters and an unknown popula

umka21 [38]

Answer:

The answer is " $(25.32, 30.68)$ "

Step-by-step explanation:

Given:

$\bar x = 28\\\\ \sigma = 4\\\\n =26\\\\$

When $98\%$ confidence level so, the z:

$\alpha = 1 - 98\% = 1 - 0.98 = 0.2\\\\\frac{\alpha}{2} =\frac{0.02}{2} = 0.01\\\\Z_{\frac{\alpha}{2}} = Z_{0.01} = 1.645\ \ \ ( Using \ z \ table )\\\\$

$E = Z_{\frac{\alpha}{2} \times ( \frac{\sigma}{\sqrt{n}})$

$= 1.645 \times (\frac{4}{\sqrt{26}})\\\\=2.68$

When 98% confidence interval estimate of the population mean is,

$\bar x - E < \mu < \bar x + E\\\\28 - 2.68 < \mu < 28 + 2.68\\\\25.32 < \mu < 30.68\\\\(25.32, 30.68)\\\\$

7 0

3 years ago