A previous survey of Washington residents showed that 18% of residents accessed a state park within the last 12 months. This year, the state would like to re-administer the survey, but wants to be sure the Margin of Error in their new study will be at most 4%. Assuming they believe the previous survey's results were reliable, how many samples should they take to ensure their Margin of Error is at most 4% if they plan to analyze the data using a 95% confidence interval

Answers

Answer 1

Using the z-distribution for the margin of error, it is found that 355 samples should be taken.

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]\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 z-score that has a p-value of [tex]\frac{1+\alpha}{2}[/tex].

The margin of error is given by:

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

The estimate is of 18%, hence [tex]\pi = 0.18[/tex].

95% confidence, hence [tex]\alpha = 0.95[/tex], z is the value of Z that has a p-value of [tex]\frac{1+0.95}{2} = 0.975[/tex], so [tex]z = 1.96[/tex].  

The minimum sample size is n for which M = 0.04, hence:

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

[tex]0.04 = 1.96\sqrt{\frac{0.18(0.82)}{n}}[/tex]

[tex]0.04\sqrt{n} = 1.96\sqrt{0.18(0.82)}[/tex]

[tex]\sqrt{n} = \frac{1.96\sqrt{0.18(0.82)}}{0.04}[/tex]

[tex](\sqrt{n})^2 = \left(\frac{1.96\sqrt{0.18(0.82)}}{0.04}\right)^2[/tex]

[tex]n = 354.4[/tex]

Rounding up, 355 samples should be taken.

A similar problem is given at https://brainly.com/question/14936818


Related Questions

Is 5.12 times 10n =512

Answers

Answer:

it is D

Step-by-step explanation:

I have to show you, but if I do it don't on the paper

The answer is D, the variables could be replaced with a five to make the statement true

Two integers are relatively prime if, and only if, their greatest common divisor is 1. For example, 2 and 3 are relatively prime, 1 and 1 are relatively prime, but 2 and 2 are not. You toss two dice, one blue and one gray. What is the probability that when the dice stop rolling that the pip count on the blue die is relatively prime to the pip count on the gray die and the gray die is showing six pips

Answers

Answer:

A woman wants to measure the height of a nearby building. She places a 7 ft pole in the shadow of the building so that the shadow of the pole is exactly covered by the shadow of the building. The total length of the building's shadow is 184 ft, and the pole casts a shadow that is 5.5ft long. How tall is the building? Round your answer to the nearest foot. (The figure is not drawn to scale.)

Step-by-step explanation:

A woman wants to measure the height of a nearby building. She places a 7 ft pole in the shadow of the building so that the shadow of the pole is exactly covered by the shadow of the building. The total length of the building's shadow is 184 ft, and the pole casts a shadow that is 5.5ft long. How tall is the building? Round your answer to the nearest foot. (The figure is not drawn to scale.)A woman wants to measure the height of a nearby building. She places a 7 ft pole in the shadow of the building so that the shadow of the pole is exactly covered by the shadow of the building. The total length of the building's shadow is 184 ft, and the pole casts a shadow that is 5.5ft long. How tall is the building? Round your answer to the nearest foot. (The figure is not drawn to scale.)A woman wants to measure the height of a nearby building. She places a 7 ft pole in the shadow of the building so that the shadow of the pole is exactly covered by the shadow of the building. The total length of the building's shadow is 184 ft, and the pole casts a shadow that is 5.5ft long. How tall is the building? Round your answer to the nearest foot. (The figure is not drawn to scale.)

Which expression represents 81 decreased by an unknown number?


81÷a

81a

81−a

81 + a

Answers

Answer:

81 - a

Step-by-step explanation:

Decreased

means to subtract

81 –

by an unknown number

means a variable such as a or x

therefor

81 – a

có 100 công nhân sản xuất trong một ngày được 1200 đợn vị sản phẩm với tổng chi phí là 2400 USD

Answers

Answer:

4 better inbox

Step-by-step explanation:

4 x ( 2 + 5 )^2 - 5^2

Answers

4* (7)^2-(5)^2
=4*49-25
=196-25
=171

What is one website you can visit in order to request free credit report from any of the three bureaus?

Answers

Answer: annualcreditreport.com

Step-by-step explanation: The only authorized website for free credit reports, or call 1-877-322-8228

Kim Barney pays a $290.00 annual premium for an insurance plan with a $500 deductible. The company pays 80% of the remaining expense. If Kim had $2,500.00 in medical expenses, calculate the following.

Answers

The amount that Kim Barney spends is $342 for medical expenses.

What is buying cost?

Buying cost is the cost at which someone buys or is willing to buy shares, bonds.( including the tax)

here, we have,

Given that,

Kim Barney pays a $290.00 yearly premium for a $500.00 deductible insurance plan. 80 percent of the remaining cost is covered by the business. If Kim has medical costs of $2,500.00

To find : The amount that Kim barney spends for the medical expenses.

If the business covers 80% of the remaining balance ($1710), they will be responsible for paying $1368 of it.

10% of 1710 is 171

171x8=1368

The insurance provider covers the $1368.

Kim Barney spends $342.

Consequently, Kim Barney spends the following amount on medical costs $342.

To learn more about the cost click here:

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Tell whether the fractions are equivalent. Write = or [tex]\neq[/tex]
3/4 ____ 8/12

Answers

not equal 3/4 x 3 = 9/12

solve the inequality x-3 < 3x -7​

Answers

Answer:

x > 2 or 2 < x

Step-by-step explanation:

x-3 < 3x-7

-3 < 2x-7

4 < 2x

2 < x

x > 2

Hi, I got 8 points off on this problem, can you help me figure out what I did wrong?

Answers

Answer:

Possible errors: Triangle classification and definition.

Step-by-step explanation:

An isoceles triangle has at least two congruent sides of the same length.  

Given the triangle that has two equal angles, and that you'll have to prove that the triangle also has two equal sides.  

Using the Converse of Isoceles Triangle Theorem, where it states that if a triangle has two congruent angles < PQR ≅ < PRQ, for which opposite sides of those angles are congruent:  

The opposite side of <PQR is line PR.The opposite side of <PRQ is line PQ.  

Additionally, connecting point P to point X along the line QR such that PX ⊥ QR, divides △PQR into two symmetrical sections, where points Q and R are equidistant from point X.      

Answer:

Possible errors: Triangle classification and definition.

Would love it if your able to help me :)

Answers

Answer:

x = 2.83163

Step-by-step explanation:

Have a nice day!

and if you have questions on how I found it please ask.

What is negative 10 divided by .22

Answers

Answer:

That would be negative 45 or - 45

Please correct me if im wrong

consider the system of equations. which shows an equivalent system of equations?
see attatched

Answers

Answer:

A.

Step-by-step explanation:

All choices show the first original equation.

Each choice shows a different second equation.

Take the second original equation:

6x + 5y = 30

Multiply both sides by -5.

-30x - 25y = -150

Answer: A.

A farmer had 21 goats all but 9 died how many survive ?

Answers

Answer:

9

Step-by-step explanation:

All but 9

Answer:

12

Step-by-step explanation:

I used a calculator I hhhhhhj

find the sum of 6/12+1/2​

Answers

6/12 + 6/12 = 1
1/2 = 6/12

Answer:

1

Step-by-step explanation:

[tex] \frac{6}{12} + \frac{1}{2} \\ = \frac{1}{2} + \frac{1}{2} \\ = \frac{2}{2} \\ = \frac{1}{1} \\ = 1[/tex]

2/3 of a cup of batter can make 5/6 of a batch of pancakes. How many cups of water are needed to make one batch of pancakes?

Answers

Answer:

1 11/12 cups of water

find the slope from the pair of the points
(-3,-4) (1,5)

Answers

Answer:

2.25

Step-by-step explanation:

m = 9 / 4 = 2.25

points belong to an increasing, linear function.

Equation: y = 2.25x + 2.75.

BRAINLIEST?

cual de estas fracciones es mayor que 2/5?explica como lo has averiguado

Answers

Answer:

33333

Step-by-step explanation:

Gene has a gasoline budget of $275 per month. He uses an average of $6 of gasoline each day he drives. Which of the following equations represents how much money is left in his gasoline budget after x days of driving?
A. y=275-6x
B. y=275+6x
C. y=6x-275
D. y=275x-6

Answers

Answer:

d because your taking away 6 from the 275

Step-by-step explanation:

Solve the inequalities from parts A and D for the variables b and n, respectively.



Part A:2b<56
Part D:n<56

Answers

Answer:

Part A: b < 28

Part D: n < 56

Step-by-step explanation:

part A: divide each term in  and simplify.

Inequality Form: b < 28

part d: this is already solved but can be shown in multiple forms.

Inequality Form: n < 56

Interval Notation: ( -∞ , 56)

the length of a rectangle in (3+√7) and it's with is (1+2√7). what is the area of the rectangle? what is the perimeter of the rectangle​

Answers

Answer:

Area: (3+√7) x (1+2√7) = 17+7√7 = 35.52

Perimeter: 2(3+√7) + 2(1+2√7) = 8+6√7 = 23.87

What is .7899 rounded 4 decimal places

Answers

.7899 rounded is .79. But in you want to convert/round it all the way it’s 1. But .79 makes more sense. Or .8. Which ever one works!!


Hope this helped. :)

a 25 -ft ladder rests against the side of a house. the distance between the top of the lader and the ground is 17 ft more than the distance between the base od the ladder and the bottom of the house. find both distances. ​

Answers

Answer:

Step-by-step explanation:

x² + (x + 17)² = 25²

x² + x² + 34x + 289 = 625

2x² + 34x - 336 = 0

x² + 17x - 168 = 0

x = (-17 ±√(17² - 4(1)(-168))) / (2(1))

x = 7 or - 24   the negative distance makes no sense, but if we plug our good answer of 7 ft in for the base length, the height comes out to be + 24 ft

base = 7 ft

height = 24 ft

Select the statements which could describe the graph of a nonproportional relationship.


Answers

Answer:

what it says iiiiiiii888i888iiiii

What is the equation for the line in slope-intercept form?

Answers

Y=-8/2x+5
Hgfxdffggggujjcfccchhjbvg

Hi guys im stuck on this maths question

(2/5)^-3

Answers

Answer:

15.625

Step-by-step explanation:

Answer:

[tex] (\frac{2}{5} ) {}^{ - 3} \\ = (\frac{a}{b} ) {}^{ - x} = (\frac{b}{a} ) {}^{x} \\ so \: \: \: \: \: \: (\frac{2}{5} ) {}^{ - 3} \\ = (\frac{5}{2} ) {}^{3} \\ = \frac{5 {}^{3} }{2 {}^{3} } \\ \: = \: \frac{125}{8} [/tex]

HELPPPPPPPPPPPPPPPPPPPPPPPPPPPPPP

Answers

Answer:

Fertilizer puts nitrogen into the soil, so using fertilizer puts more nitrogen into the carbon cycle.

When you use fertilizer, its because a certain plant you are planting uses all the nitrogen in the soil, so it won't grow next time. Too much fertilizer, though, would burn up your plant (not literally). Some plants put their own nitrogen into the soil. I can't think of one off the top of my head, but I believe potatoes do. Anyways, this is where crop rotation came into play.

Things like corn take a lot of nitrogen, so the next time you had to plant whatever plant potatoes, which again may be wrong, in order to get nitrogen for the corn to grow next season. Today we have fertilizer, so we can give them nitrogen while they grow, instead of putting in other plants, taking more time.

So really, it doesn't do much, because your plant takes all the nitrogen that the Fertilizer adds.

Answer:

People have been converting atmospheric nitrogen into nitrogen fertilizers and then applying the fertilizers to plants in to grow more crops. This has previously been quite effective, allowing individuals to farm on previously unproductive lands, and provide adequate food for expanding populations of people. Unfortunately, fertilizers are frequently overused, which can lead to issues.

Nitrogen from fertilizers excretes into soils, typically promoting the growth of weeds rather than native vegetation. Nitrogen then washes into streams, resulting in a nutrient overload, a phenomenon known as eutrophication.

Eutrophication causes aquatic weeds to proliferate excessively in freshwater lakes. These aquatic weeds  occasionally occupy entire lakes, streams, or rivers. Green algae cloud the water, and gooey algal slime covers the shallow rocks. 

When nitrogen-rich waters flow down into the ocean, they worsen the situation. High nitrogen concentrations in the Mississippi River Delta have generated a 'dead zone' where the water flows into the Gulf of Mexico. This has occurred every summer for over 30 years. In 2001, this dead zone, where oxygen levels are too low for species to thrive, encompassed over 8000 square miles of water. It occurs when nitrogen in the water enables algae to quickly grow out of control.

Step-by-step explanation:

Great article to look at for more information -

https://www.nytimes.com/2017/07/27/climate/nitrogen-fertilizers-climate-change-pollution-waterways-global-warming.html

negative seven times a number is negative two hundred forty five. what is the number?



pleasee i need help

Answers

Answer:

35

Step-by-step explanation:

since i couldn't answer before

Answer the following questions,
0
(a) What number is 95% of 80
0
(b) 85% of what is 51?

Answers

Answer:

95% of 80 is 76 and 85% of 60 is 51.

Step-by-step explanation:

Answer:

a. 76,  b. 60.

Step-by-step explanation:

a)  80 * 0.95 = 76.

b)   0.85 x = 51

x = 51/0.85 = 60.

Mr. and Mrs. Bruce took a boat trip which left Cala for Friends’ Island at 11:45 in the morning. The trip lasted for 1 hour and 20 mins. When did they arrive at Friends’ Island?

Answers

they arrived at 1:05
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