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2 years ago

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Từ điểm A ở ngoài (O) kẻ các tiếp tuyến AB, AC với đường tròn (B và C là các tiếp điểm), BC cắt OA tại D, trên cung nhỏ BC lấy E

, ED cắt (O) tại F chứng minh góc BAE = góc CAF

1 answer:

Neko [114]2 years ago

4 0

I don’t understand what is that

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From his eye, which stands 1.59 meters above the ground, Francisco measures the

viva [34]

The height of the skyscraper to the nearest tenth is 234. 95 meters.

<h3>How to determine the height</h3>

From the information given, we have:

angle of elevation = 32°
length of the base, adjacent side = 376 meters
height of the skyscraper, opposite side = x meters

To determine the height of the elevator, let's use the tangent identity

We have that;

tan θ = opposite/ adjacent

The value of the opposite side is 'x' which is the height of the skyscraper and the value of the adjacent side is 376 meters which is the length of the base of the skyscraper

Now, substitute the values, we have;

tan 32 = x/ 376

cross multiply

x = tan 32 × 376

x = 0. 6249 × 376

x = 234. 95 meters

We know that the 'x' represents the opposite side and thus the height of the skyscraper

Thus, the height of the skyscraper to the nearest tenth is 234. 95 meters.

Learn more about angle of elevation here:

brainly.com/question/19594654

#SPJ1

7 0

2 years ago

I Need help please I only have a little bit of time

kvasek [131]

Answer:

30

Step-by-step explanation:

if its asking for inches

6 0

3 years ago

Read 2 more answers

Write an equation describing the relationship of the given variables. y varies inversely as the cube root of x and when x=125, y

notka56 [123]

Answer:

y = 40 / x^1/3

Step-by-step explanation:

Given that :

y α x^1/3

y = k * 1 / x^1/3

y = k / x^1/3

When x = 125 ; y = 8

8 = k / 125^1/3

Cube root of 125 = 5

8 = k / 5

8 * 5 = k ; k = 40

Hence, expression becomes :

y = 40 / x^1/3

4 0

3 years ago

A government report gives a 99% confidence interval for the proportion of welfare recipients who have been receiving welfare ben

juin [17]

Answer:

The estimation for the proportion for this case is $\hat p = 0.21$

And we know that the 99% confidence interval is given by:

$0.21 \pm 0.045$

So then the margin of error at 99% of confidence is 0.045, and the margin of error is given by this formula:

$ME= z_{\alpha/2} \sqrt{\frac{\hat p(1-\hat p)}{n}}$

If we decrease the confidence level this margin of error can't be higher than 0.045 so then the correct answer for this case would be:

d. 21% ± 4.8%

Because if the z value decrease from 2.58 to 1.96 not makes sense that the margin of error increase from 0.045(4.5%) to 0.048(4.8%)

Step-by-step explanation:

Previous concepts

A confidence interval is "a range of values that’s likely to include a population value with a certain degree of confidence. It is often expressed a % whereby a population means lies between an upper and lower interval".

The margin of error is the range of values below and above the sample statistic in a confidence interval.

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".

Solution to the problem

The population proportion have the following distribution

$p \sim N(p,\sqrt{\frac{\hat p(1-\hat p)}{n}})$

The confidence interval would be given by this formula

$\hat p \pm z_{\alpha/2} \sqrt{\frac{\hat p(1-\hat p)}{n}}$

For the 95% confidence interval the value of $\alpha=1-0.95=0.05$ and $\alpha/2=0.025$ , with that value we can find the quantile required for the interval in the normal standard distribution.

$z_{\alpha/2}=1.96$

For the 99% confidence interval the value of $\alpha=1-0.99=0.01$ and $\alpha/2=0.005$ , with that value we can find the quantile required for the interval in the normal standard distribution.

$z_{\alpha/2}=2.58$

The estimation for the proportion for this case is $\hat p = 0.21$

And we know that the 99% confidence interval is given by:

$0.21 \pm 0.045$

So then the margin of error at 99% of confidence is 0.045, and the margin of error is given by this formula:

$ME= z_{\alpha/2} \sqrt{\frac{\hat p(1-\hat p)}{n}}$

If we decrease the confidence level this margin of error can't be higher than 0.045 so then the correct answer for this case would be:

d. 21% ± 4.8%

Because if the z value decrease from 2.58 to 1.96 not makes sense that the margin of error increase from 0.045(4.5%) to 0.048(4.8%)

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3 years ago

A movie was 3 1/2 hours long if Lilly turned of the movie off 1/4 of the way through how much time did she spend watching

Nuetrik [128]

Answer:

7/8 of an hour

Step-by-step explanation:

7 0

3 years ago

Read 2 more answers