12. Un artículo vale 80 dólares después de aplicarle el IVA del 20% ¿Cuánto valdría sin IVA

There are 2,000 eligible voters in a precinct. A total of 500 voters are randomly selected and asked whether they plan to vote f

Ann [662]

Answer:

$0.7 - 2.58 \sqrt{\frac{0.7(1-0.7)}{500}}=0.647$

$0.7 + 2.58 \sqrt{\frac{0.7(1-0.7)}{500}}=0.753$

And the 99% confidence interval would be given (0.647;0.753).

So the correct answer would be:

a. 0.647 and 0.753

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".

The population proportion have the following distribution

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

Solution to the problem

The estimated population proportion for this case is:

$\hat p = \frac{350}{500}=0.7$

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 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.

$z_{\alpha/2}=2.58$

And replacing into the confidence interval formula we got:

$0.7 - 2.58 \sqrt{\frac{0.7(1-0.7)}{500}}=0.647$

$0.7 + 2.58 \sqrt{\frac{0.7(1-0.7)}{500}}=0.753$

And the 99% confidence interval would be given (0.647;0.753).

So the correct answer would be:

a. 0.647 and 0.753

7 0

3 years ago

Whats 6 divided into 9.29

wel

1.5483 repeating

Hope this helped :)

5 0

3 years ago

Please help me thankyou lol

vampirchik [111]

Answer:

Yes, they are congruent

Step-by-step explanation:

They are congruent because they both have same length sides

8 0

3 years ago

choose an equation in slope-intercept form for the line that passes through (-8,1) and is perpendicular to the y=2x-17. select o

Fed [463]

Y = 2x - 17, comparing to y = mx + c, slope m = 2.

If perpendicular, the new slope would be -1/2, that is the negative reciprocal of 2.

And passing through (-8 , 1).

using y = mx + c, and x = -8, y = 1, m = -1/2

1 = -1/2*-8 + c

1 = 4 + c

1 - 4 = c

c = -3

y = mx + c, substituting m = -1/2, and c = -3, y = -(1/2)x - 3.

Option C.

5 0

3 years ago

Solve the equation sin^2 x=3 cos ^2 x

larisa86 [58]

Answer:

Step-by-step explanation:

Answer:

x

=

π

3

,

2

π

3

,

4

π

3

,

5

π

3

Explanation:

(

sin

x

)

2

=

3

(

cos

x

)

2

(

sin

x

)

2

=

3

(

1

−

(

sin

x

)

2

)

(

sin

x

)

2

=

3

−

3

(

sin

x

)

2

4

(

sin

x

)

2

=

3

(

sin

x

)

2

=

3

4

sin

x

=

±

(

√

3

2

)

x

=

π

3

,

π

−

π

3

,

π

+

π

3

,

(

2

π

)

−

π

3

x

=

π

3

,

2

π

3

,

4

π

3

,

5

π

3

If this was in the region

0

≤

x

≤

2

π

6 0

3 years ago

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