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2 years ago

If BC = 4 and CD = 27, find AC.

Mathematics

1 answer:

jek_recluse [69]2 years ago

5 0

$\Delta ABC\sim\Delta DAC\\\\then\\\\\frac{|AC|}{|BC|}=\frac{|CD|}{|AC|}\\\\|AC|^2=|BC|\cdot|CD|\\\\|AC|^2=4\cdot27\\\\|AC|=\sqrt{4\cdot27}\\\\|AC|=\sqrt4\cdot\sqrt{27}\\\\|AC|=2\cdot\sqrt{9\cdot3}\\\\|AC|=2\sqrt9\cdot\sqrt3\\\\|AC|=2\cdot3\sqrt3\\\\|AC|=6\sqrt3$

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Two boxes of apples contain a total of 24 apples. If you halve the number of apples in the first box and add 4 apples to the sec

maks197457 [2]

Step-by-step explanation:

let the no.s of apples in the one box be=x

then no.s of apples in the 2nd box =24-x

according to the question,

24-x+4=20

-x= 20-28

-x=-8

x= 8

no.s of apples in one box= 8

and no.s of apples in another box=24-8= 16

option C

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2 years ago

Read 2 more answers

A clinical trial tests a method designed to increase the probability of conceiving a girl. In the study 335335 babies were born

strojnjashka [21]

Answer:

The 99% confidence interval estimate of the percentage of girls born is (74.37%, 85.63%).

Usually, 50% of the babies are girls. This confidence interval gives values considerably higher than that, so the method to increase the probability of conceiving a girl appears to be very effective.

Step-by-step explanation:

Confidence Interval for the proportion:

In a sample with a number n of people surveyed with a probability of a success of $\pi$ , and a confidence level of $1-\alpha$ , we have the following confidence interval of proportions.

$\pi \pm z\sqrt{\frac{\pi(1-\pi)}{n}}$

In which

z is the zscore that has a pvalue of $1 - \frac{\alpha}{2}$ .

For this problem, we have that:

$n = 335, \pi = \frac{268}{335} = 0.8$

99% confidence level

So $\alpha = 0.01$ , z is the value of Z that has a pvalue of $1 - \frac{0.01}{2} = 0.995$ , so $Z = 2.575$ .

The lower limit of this interval is:

$\pi - z\sqrt{\frac{\pi(1-\pi)}{n}} = 0.8 - 2.575\sqrt{\frac{0.8*0.2}{335}} = 0.7437$

The upper limit of this interval is:

$\pi + z\sqrt{\frac{\pi(1-\pi)}{n}} = 0.8 + 2.575\sqrt{\frac{0.8*0.2}{335}} = 0.8563$

For the percentage:

Multiplying the proportions by 100.

The 99% confidence interval estimate of the percentage of girls born is (74.37%, 85.63%).

Usually, 50% of the babies are girls. This confidence interval gives values considerably higher than that, so the method to increase the probability of conceiving a girl appears to be very effective.

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2 years ago

A group of 6 students is surveying their classmates to get feedback about different clubs they're involved in. If each surveys m

galben [10]

Answer:

The domain would be given by <u>D = {X ≥ 2} X = [2, Z].</u> Since the variable Z is the number of children in the school. And the 6 children should not survey the same person, it would be Z / 6 for each interviewer.

Step-by-step explanation:

- If the group of children surveys more than 2 classmates, it means that the number with which the survey begins is 12 students.

And since the maximum number of students in the school is given by the variable of Z, then Z is the number with which the domain closes.

The rank would be given by the set of [2, Z]

Z / 6 being the maximum number of children surveyed by 1 interviewer.

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2 years ago

Y = –3x 6 y = 9 what is the solution to the system of equations? (–21, 9) (9, –21) (–1, 9) (9, –1)

Romashka [77]

we have

<u>The system of equations</u>

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