A student uses the Distributive Property to rewrite 18+54. Which expression could the student use?

You want to obtain a sample to estimate a population proportion. At this point in time, you have no reasonable preliminary estim

pogonyaev

Answer:

$n=\frac{0.5(1-0.5)}{(\frac{0.025}{1.28})^2}=655.36$

And rounded up we have that n=656

Step-by-step explanation:

In order to find the critical value we need to take in count that we are finding the interval for a proportion, so on this case we need to use the z distribution. Since our interval is at 80% of confidence, our significance level would be given by $\alpha=1-0.80=0.20$ and $\alpha/2 =0.10$ . And the critical value would be given by:

$z_{\alpha/2}=\pm 1.28$

Solution to the problem

The margin of error for the proportion interval is given by this formula:

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

Since we don't have prior info for the proportion of interest we can use $\hat p=0.5$ as estimator. And on this case we have that $ME =\pm 0.025$ and we are interested in order to find the value of n, if we solve n from equation (a) we got:

$n=\frac{\hat p (1-\hat p)}{(\frac{ME}{z})^2}$ (b)

And replacing into equation (b) the values from part a we got:

$n=\frac{0.5(1-0.5)}{(\frac{0.025}{1.28})^2}=655.36$

And rounded up we have that n=656

5 0

3 years ago

At any point in time, there could be bicycles, tricycles, and

Aleksandr-060686 [28]

Answer:

There may be 1 or 3 tricycles in the parking lot.

Step-by-step explanation:

Since at any point in time, there could be bicycles, tricycles, and cars in the school parking lot, and today, there are 53 wheels in total, if there are 15 bicycles, tricycles, and cars in total, to determine how many tricycles could be in the parking lot, the following calculation must be performed:

13 x 4 + 1 x 3 + 1 x 2 = 57

11 x 4 + 1 x 3 + 3 x 2 = 53

10 x 4 + 3 x 3 + 2 x 2 = 53

8 x 4 + 5 x 3 + 2 x 2 = 51

10 x 2 + 1 x 3 + 4 x 4 = 39

9 x 3 + 1 x 2 + 5 x 4 = 49

Therefore, there may be 1 or 3 tricycles in the parking lot.

6 0

3 years ago

Given: sin ∅= 4/5 and cos x = -5/13 ; evaluate the following expression.<br><br> tan( ∅ - x )

Pavlova-9 [17]

By definition of tangent,

tan(θ - x) = sin(θ - x) / cos(θ - x)

Expand the sine and cosine terms using the angle sum identities,

sin(x ± y) = sin(x) cos(y) ± cos(x) sin(y)

cos(x ± y) = cos(x) cos(y) ∓ sin(x) sin(y)

from which we get

tan(θ - x) = (sin(θ) cos(x) - cos(θ) sin(x)) / (cos(θ) cos(x) + sin(θ) sin(x))

Also recall the Pythagorean identity,

cos²(x) + sin²(x) = 1

from which we have two possible values for each of cos(θ) and sin(x):

cos(θ) = ± √(1 - sin²(θ)) = ± 3/5

sin(x) = ± √(1 - cos²(x)) = ± 12/13

Since there are 2 choices each for cos(θ) and sin(x), we'll have 4 possible values of tan(θ - x) :

• cos(θ) = 3/5, sin(x) = 12/13 :

tan(θ - x) = -56/33

• cos(θ) = -3/5, sin(x) = 12/13 :

tan(θ - x) = 16/63

• cos(θ) = 3/5, sin(x) = -12/13 :

tan(θ - x) = -16/63

• cos(θ) = -3/5, sin(x) = -12/13 :

tan(θ - x) = 56/33

7 0

2 years ago

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if U={natural number less than 10}, M={multiples of 2}, N={factors of 8} and O={even number} then can we write M intersection (N

mr_godi [17]

Answer:

yes

Step-by-step explanation:

u={1,2,3,4,5,6,7,8,9}

m={2,4,6,8}

N={1,2,4,8}

O={2,4,6,8}

Now

M intersection (N intersection O) = (M intersection N) intersection O

or , {2,4,6,8} intersection {2,4,8} ={2,4,8}

intersection {2,4,6,8 }

:. {2,4,8} ={2,4,8}

7 0

3 years ago

What is the slope of the line that passes through (-3,2) and (1,2)

TEA [102]

(-3,2)(1,2)...notice that the y values are the same.....when the y values are the same u have a horizontal line with a 0 slope.

IF the x values would have been the same (instead of the y values), then u would have had a vertical line with an undefined slope.

6 0

3 years ago

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