the length of a road is 1000 miles. if 1 inch represents 100 miles, what is the length of the road on the map?

Answer:

a) A sample of 385 must be taken.

b) The 95% confidence interval for the proportion of workers who have changed jobs within the past year is (0.1216, 0.2784).

c) A sample of 246 is needed.

Step-by-step explanation:

Question a:

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

[tex]\pi \pm z\sqrt{\frac{\pi(1-\pi)}{n}}[/tex]

In which

z is the zscore that has a pvalue of [tex]1 - \frac{\alpha}{2}[/tex].

The margin of error is:

[tex]M = z\sqrt{\frac{\pi(1-\pi)}{n}}[/tex]

Absence of preliminary data:

This means that we use [tex]\pi = 0.5[/tex], which is when the largest sample will be needed.

95% confidence level

So [tex]\alpha = 0.05[/tex], z is the value of Z that has a pvalue of [tex]1 - \frac{0.05}{2} = 0.975[/tex], so [tex]Z = 1.96[/tex].

How large a sample must be taken to ensure that a 95% confidence interval will specify the proportion to within ±0.05?

A sample of n must be taken.

n is found when [tex]M = 0.05[/tex]. So

[tex]M = z\sqrt{\frac{\pi(1-\pi)}{n}}[/tex]

[tex]0.05 = 1.96\sqrt{\frac{0.5*0.5}{n}}[/tex]

[tex]0.05\sqrt{n} = 1.96*0.5[/tex]

Dividing both sides by 0.05

[tex]\sqrt{n} = 1.96*10[/tex]

[tex](\sqrt{n})^2 = (19.6)^2[/tex]

[tex]n = 384.16[/tex]

Rounding up,

A sample of 385 must be taken.

Question b:

In a sample of 100 workers, 20 of them had changed jobs within the past year.

This means that [tex]n = 100, \pi = \frac{20}{100} = 0.2[/tex]

The lower limit of this interval is:

[tex]\pi - z\sqrt{\frac{\pi(1-\pi)}{n}} = 0.2 - 1.96\sqrt{\frac{0.2*0.8}{100}} = 0.1216[/tex]

The upper limit of this interval is:

[tex]\pi + z\sqrt{\frac{\pi(1-\pi)}{n}} = 0.2 + 1.96\sqrt{\frac{0.2*0.8}{100}} = 0.2784[/tex]

The 95% confidence interval for the proportion of workers who have changed jobs within the past year is (0.1216, 0.2784).

Question c:

Same procedure as question a, just with [tex]\pi = 0.2[/tex]

[tex]M = z\sqrt{\frac{\pi(1-\pi)}{n}}[/tex]

[tex]0.05 = 1.96\sqrt{\frac{0.2*0.8}{n}}[/tex]

[tex]0.05\sqrt{n} = 1.96\sqrt{0.2*0.8}[/tex]

[tex]\sqrt{n} = \frac{1.96\sqrt{0.2*0.8}}{0.05}[/tex]

[tex](\sqrt{n})^2 = (\frac{1.96\sqrt{0.2*0.8}}{0.05})^2[/tex]

[tex]n = 245.8[/tex]

Rounding up

A sample of 246 is needed.

Answer:

Equation: 4.8 times 5.2 then divided by 2

= 12.48 (area)

Step-by-step explanation:

The formula of finding the area of a triangle:

base * height then divided by 2

* = multiply

Base: 4.8

Height: 5.2

multiply them

= 24.96

then divide by 2

= 12.48

hope this helped :)

Answer:

12.48

Step-by-step explanation:

5.2 times 4.8 is is 24.96 and that divded by 2 is 12.48

Answer:

               1872

Step-by-step explanation

Answer:

5/12 cup of water per plant

Answer:

B

Step-by-step explanation:

Answer:

(6*y130896+1%315£&+)

(19+!re

Answer:

3/5

Step-by-step explanation:

5/5 - 2/5 = 3/5

Answer:

59/8

Step-by-step explanation:

Multiply the whole number by the denominator.

[tex]7 * 8 = 56[/tex]

Add the numerator to the product.

[tex]56 + 3 = 59[/tex]

Write the sum over the denominator.

[tex]\boxed{\frac{59}{8}}[/tex]

Hope this helps.

Answer:

x=9

y=20

Step-by-step explanation:

6/8=3/4

x/12=9/12=3/4

15/y=15/20=3/4

answer:

i believe 28

Step-by-step explanation:

Answer:

65

Step-by-step explanation:

Hi,

Triangles will always add up to 180 degrees. So, 62 + 53 = 115. Subtract it from 180, 180 - 115, and you get 65.

I hope this helps :)

Answer:

65

Step-by-step explanation:

The sum of the three angles of any triangle is equal to 180 degrees

Answer:

uhh 7 maybe?

Step-by-step explanation:

i dont know

Answer:

ANSWER

l

Or

Or

EXPLANATION

The given line has slope,

and

We can find the equation in the point slope form, which is given by,

We substitute the point and slope to get,

We can also simplify further to get,

We make y the subject to get,

This is called the slope intercept form.

We could also write in standard form to get

Or

Answer:

4

Step-by-step explanation:

The pre-image is the starting coordinates and it then gets larger. when you multiply four by 3 you get 12 and when you multiply four by -4 you get 16. So the pre-image dilated by 4.

Answer:

acute, equilateral

Step-by-step explanation:

Answer:

Acute, equilateral

Step-by-step explanation:

Angle of 60 is acute and it is an equilateral triangle.

Answer:

175 /2

Step-by-step explanation:

The scale factor of the image after the dilation is k = 2

Given data ,

Polygon ABCD with vertices at A(1,-1) B(3,-1), C(3,-2) and D(1-2)

Now , the dilated polygon is represented as A'B'C'D'

where the coordinates are A’(2,-2), B(6,-2), C’(6,-4) and D’(2,-4).

Now , we can compare the corresponding side lengths of the two polygons to determine the scale factor:

Scale factor = (corresponding side length of dilated polygon) / (corresponding side length of original polygon)

So, A'/A = 2 / 1

A' = 2A

So, the scale factor is k = 2

Hence , the dilation is solved.

To learn more about dilation click :

https://brainly.com/question/13176891

#SPJ1

Answer:

XWZ and ZWX are the only ways to label this angle

Step-by-step explanation:

Step-by-step explanation:

Supplementary angles add up to 180

Complementary angles add up to 90

you can check those angles by adding them up

121+59=180                 Supplementary

49+51=100                  Neither

25+65=90                  Complementary

Hope that helps :)

Step-by-step explanation:

Answer:

m = -3/4

Step-by-step explanation:

-5 - 1 / 6 - -2 = -6/8 = -3/4

Answer:

Step-by-step explanation:

(-5 - 1)/(6 + 2)= -6/8 = -3/4

Answer:

a) a = 12s

Step-by-step explaination:

Answer:

25

Step-by-step explanation:

10n−5(2n−5)

Distribute:

=10n+(−5)(2n)+(−5)(−5)

=10n+−10n+25

Combine Like Terms:

=10n+−10n+25

=(10n+−10n)+(25)

=25

plz mark me as brainliest.

Answer: 25

Step-by-step explanation:

Given

 10n-5(2n-5)

Distributive property

=10n-(5×2n-5×5)

Simplify

=10n-(10n-25)

Take off parenthesis (REMEMBER to change signs whenever it is "-" outside)

=10n-10n+25

=0+25

=25

Hope this helps!! :)

Please let me know if you have any questions

Answer:

the lines are perpendicular because they have the same slope so the correct answer would be c

Step-by-step explanation:

<4=22°

Answer:

<4+158=180 co interior angle

<4=180-158=22°

Answer:

solution given:

<4+<158°=180°[co- interior angle]

<4=180°-<158°=22°

<4=22° is your answer

Answer:  

70 + 2 + 0.3 + (-30) + (-9) + (-0.1) = 70 + (-30) + 2 + (-9) + 0.3 + (-0.1)  

Step-by-step explanation:  

i dont have an explanation but that is the answer i can confirm because i did it and got it wrong but then it showed the right answer hope it helps you

Answer:

here i gotchu mate:)

Step-by-step explanation:

To find the transformation, compare the function to the parent function and check to see if there is a horizontal or vertical shift, reflection about the x-axis or y-axis, and if there is a vertical stretch.

Shifted down  

3

units