The water works commission needs to know the mean household usage of water by the residents of a small town in gallons per day. They would like the estimate to have a maximum error of 0.14 gallons. A previous study found that for an average family the standard deviation is 2 gallons and the mean is 16 gallons per day. If they are using a 95% level of confidence, how large of a sample is required to estimate the mean usage of water

Answers

Answer 1

Answer:

A sample of 784 is required to estimate the mean usage of water.

Step-by-step explanation:

We have that to find our [tex]\alpha[/tex] level, that is the subtraction of 1 by the confidence interval divided by 2. So:

[tex]\alpha = \frac{1 - 0.95}{2} = 0.025[/tex]

Now, we have to find z in the Z-table as such z has a p-value of [tex]1 - \alpha[/tex].

That is z with a pvalue of [tex]1 - 0.025 = 0.975[/tex], so Z = 1.96.

Now, find the margin of error M as such

[tex]M = z\frac{\sigma}{\sqrt{n}}[/tex]

In which [tex]\sigma[/tex] is the standard deviation of the population and n is the size of the sample.

The standard deviation is 2 gallons

This means that [tex]\sigma = 2[/tex]

They would like the estimate to have a maximum error of 0.14 gallons. How large of a sample is required to estimate the mean usage of water?

This is n for which M = 0.14. So

[tex]M = z\frac{\sigma}{\sqrt{n}}[/tex]

[tex]0.14 = 1.96\frac{2}{\sqrt{n}}[/tex]

[tex]0.14\sqrt{n} = 1.96*2[/tex]

[tex]\sqrt{n} = \frac{1.96*2}{0.14}[/tex]

[tex](\sqrt{n})^2 = (\frac{1.96*2}{0.14})^2[/tex]

[tex]n = 784[/tex]

A sample of 784 is required to estimate the mean usage of water.


Related Questions

Determine whether (a) x = -1 or (b) x = 2 is a solution to this equation

Answers

Answer:

x = 2 is the solution to x + 1.5 = 3.5

Step-by-step explanation:

x + 1.5 = 3.5

   -1.5      -1.5

--------------------

x = 2

look at the image below

Answers

that's what I got, you can confirm if it's correct or not... I'm not sure

have a nice dayʘ‿ʘ

Cuánto es 324 por 171

Answers

Answer:

la respuesta es 55,404

I hope this helped

A garden table and a bench cost $717 combined. The garden table costs $67 more than the bench. What is the cost of the bench?

Answers

Subtract the difference form the total:

717 - 67 = 650

Divide the remaining amount by 2:

650/2 = 375

The bench cost$375

What steps are included in the construction of a perpendicular line through a point on a line

Answers

Answer:

A perpendicular line from a given point

Place your compass on the given point (point P).

From each arc on the line, draw another arc on the opposite side of the line from the given point (P).

Use your ruler to join the given point (P) to the point where the arcs intersect (Q).

Answer:

get the slope of original line

take the inverse of the slope and multiply by -1 (2/3 becomes - 3/2)

y = -b/a x + b

plug on y & x using the given point

calculate the "B"

go back to the y = -b/ax + calculated "B"

that is your answer

Step-by-step explanation:

by solving a pair of linear equation X + Y is equal to 20 and x-y=10 the value of 'x' and 'y' are​

Answers

Answer:

x=15, y=5

Step-by-step explanation:

x+y=20

x-y=10

Adding both equations;

(x+x) + (y-y) = 20+10

2x = 30

x = 30/2 = 15

Substitute x=15 into x+y=20

y= 20-x = 20-15= 5

Determine whether the ordered pair is a solution of the equation. Show your work to receive credit.

9. Is (-1,3) a solution to the equation y = -3x + 10?

10. Is (7,-2) a solution to the equation x – 4y = 15?

Please show work to help me understand.

Answers

Answer:

3=3 + 10

3 = 13(NO)

x-4y=15

7--8=15

15=15(YES)

Select the correct answer.
As part of a class project, a university student surveyed the students in the cafeteria lunch line to look for a relationship between eye color and hair color among students. The table below contains the results of the survey.

Answers

Answer: Choice B)  0.27

=========================================================

Explanation:

There are a lot of data values here, and it's possible to easily get lost in them. However, we're asked only about students with blond hair. So we only focus on the first row. Ignore everything else.

We see that there are 78 of these students total. Of this total, 21 have green eyes.

Therefore, the relative frequency of blonds with green eyes is 21/78 = 0.2692 which rounds to 0.27; so that's why the answer is choice B.

find the value and express it in standard form : 5×10^8×2×10^11​

Answers

Answer:

1*10^20

Step-by-step explanation:

5×10^8×2×10^11= 5*2*10^(8+11)= 10*10^19= 10^ (1+19)= 10^20= 1*10^20.

5×10⁸×2×10¹¹5×2×10⁸×10¹¹10×10¹⁹10²⁰100,000,000,000,000,000,0001E20

please mark this answer as brainlist

In a certain country people own a total of about 352 million fish, cats, and dogs as pets. The number of fish owned is 14 million more than the total number of cats
and dogs owned, and 11 million more cats are owned than dogs. How many of each type of pet do people in this country own?

Answers

Answer:

dogs = 79

dats = 90

fish = 183

Step-by-step explanation:

let the total number of dogs owned be x

no. of cats owned = x+11

no. of fish owned = x+11+x+14= 2x+25

hence,

2x+25+x+11+x=352

4x=316

x=316/4= 79mil

no. of cats owned = 79 + 11 = 90

no. of fish owned = 2(79)+25=183

Chen rode his skateboard 3/3/4 miles in 34 of an hour.

What was his average speed in miles per hour?

_[blank]_ miles per hour

Answers

Answer:

5 miles per hour

Step-by-step explanation:

3¾ ÷ ¾ =

15/4 ÷ ¾ =

15/4 x 4/3 =

15/3 = 5

Picking a card and spinning a spinner are independent events.

True
False

Answers

Answer:

True

Step-by-step explanation:

Both happened in different times and are seprate events

PLEASE HELP WITH BOTH OF THESE ASAP!

Answers

Answer:

Hello,

Step-by-step explanation:

[tex]\overline{x}=3262\\\sigma=1100\\\\P(x\geq 1000)=P(x\leq 3262+(3262-1000))=P(x\leq 5524)\\\\z=\dfrac{x-\overline{x}}{\sigma} =\dfrac{5524-3262}{1100} =2.05\overline{63}\\\\\\P(z\leq 2.05)=0.9789\\\\P(z\leq 2.06)=0.9803\\\\\\\boxed{0.9789\leq P\leq 0.9803}\\\\\\[/tex]

[tex]P(x\leq 4000)=P(z\leq \dfrac{4000-3262}{1100} )=P(z\leq 0.67\overline{09})\\\\P(z\leq 0.67)=0.7486\\P(z\leq 0.68)=0.7517\\\\0.7486\leq P\leq 0.7517\\[/tex]

If 2/3 of the girls in class have brown eyes and 1/4 of the girls have blue eyes what fraction of the girls in class have neither blue or brown

Answers

1/12, make the denominators the same by making the 12 that makes 8/12 and 3/12 together it’s 11/12 which means 1/12 I not blue or brown

Cheyenne's bi-weekly gross pay is $529.81. She sees that $18.54 was deducted for Medicare tax. What percent of Cheyenne's gross pay has been withheld for Medicare tax? Round to the nearest tenth. (2 points)
0.35%
2.2%
3.5%

Answers

18.54/529.81= 0.0349
0.0349*100=3.49%= 3.5%

Answer:

I got 3.5%

Step-by-step explanation:

Hope this helps

find the LCM of 220,440,660 by common division method​

Answers

Answer: LCM = 1320

Step-by-step explanation:

2 | 220, 440, 660

2 | 110, 220, 330

2 | 55, 110, 165

3 | 55, 55,165

5 | 55, 55 , 55

11 | 11, 11, 11

| 1, 1, 1

= 2 × 2 × 2 × 3 × 5 × 11

= 1320

Therefore the LCM is 1320

Must click thanks and mark brainliest

6 times the sum of 5 and K​

Answers

Answer:

6(5+k)

Step-by-step explanation:

The sum of 5  and k

5+k

6 times the sum

6(5+k)

The polynomial p(x) = x3 – 7x - 6 has a known factor of (x + 1).
Rewrite p(x) as a product of linear factors.
p(x)

Answers

Hi there!

[tex]\large\boxed{(x -3)(x + 2)(x + 1)}[/tex]

We can use long division to find the other roots of p(x).

We know that x + 1 is a factor, so:

Set up:

Find how many times that the first term in the divisor goes into the first of the dividend. Subtract from like terms.

         x² - x - 6

x + 1 | x³ + 0x² - 7x - 6

         x³ + x²

         0 - x²     - 7x

            - x²      - x

             0        - 6x - 6

                        -6x - 6

                          0     0

Therefore, x² - x - 6 is another factor. We can factor this further:

Find two numbers that add up to -1 and multiply into -6. We get:

-3, 2

(x - 3)(x + 2)

The entire polynomial factored is:

(x -3)(x + 2)(x + 1)

Canada has a population of 33 million while Russia has 144 million inhabitants. Indonesia population is 50% greater then that of Russia while it is only 72% of the population of the United States. How many million people must be added to the United States so that the population of that country becomes 10 times of Canada?

Answers

Answer: 30 million people must be added.

Step-by-step explanation: 50% of 144 million is 72 million. You add these to find Indonesia’s population. 144 million + 72 million= 216 million. If 216 million is only 72% of the US population, then divide 216 million by 72 to find 1%. 216 million/72=3 million. Multiply this by 100 to find the US population. 3 million times 100= 300 million. Now, multiply Canada’s population by 10. 33 million times 10= 330 million. Finally, subtract 300 million from 330 million to find the amount needed to make the US population 10 times that of Canada’s. 330 million-300 million=30 million. So , you need 30 million people in order to make the US population 10 times that of Canada’s.

Solve for the value of x

Answers

Answer:

Step-by-step explanation:

This is the Law of Cosines. Use the following formula:

[tex]5.1^2=3.3^2+3.3^2-2(3.3)(3.3)cos(x)[/tex] and simplify to

26.01 = 10.89 + 10.89 - 21.78cos(x) and a bit more to

4.23 = -21.78cos(x) and finally to

-.194214876 = cos(x) and use the 2nd button along with the cos button to find that the missing angle is 101.2 degrees

The table below shows the number of pets kept by the students in a class.
-----------------------------------------------------------
No. of pets | No. of students
-----------------------------------------------------------
0 | 9
1 | k
2 | 2
3 | 1
4 | 2
-----------------------------------------------------------
If the median number of pets is 1, what is the smallest value of k ?

Answers

Answer:

The answer for this question is 5

1. Plot the following points by hand or using an online graphing calculator. What is the function that best fits the points?
(0, 3), (1, 6), (2, 12), (3, 24)

•Linear

•Exponential

•Quadratic

Answers

Exponential. This is an exponential function since it’s being multiplied by a constant rate. That rate is 2. The y axis is constantly being multiplied by 2. 3*2 is 6, 6*2 is 12, 12*2 is 24.

2. The cost of 5 pen is Rs 1200, find the cost of 1 pen.​

Answers

Step-by-step explanation:

cost of 5 pen is Rs 1200,

cost of 1 pen is 1200/5 = Rs 240

Answer:

Rs 240

Step-by-step explanation:

1200÷5=240

I NEED THE ANSWER SOON PLEASE!!?!?! hopefully someone sees this

Answers

Answer:

1 and 1/25

Step-by-step explanation:

X
у
Which equation could be used to create the data shown in the
table?
1
5
O y = 5x
4
17
O y = 5x + 1
5
21
O y = 4x + 1
7
29
O y = x + 4
9
37

Answers

Answer:

C

Step-by-step explanation:

The equation that represents the table is y=4x+1

look at the question below in the image

Answers

Answer:

117.8

Step-by-step explanation:

Surface area of a cone = πrl+πr², where r = radius and l = slant height

πrl

= π×3×9.5+π×3²

= 75π/2

= 117.8 (rounded to the nearest tenth)

Make mathematical expressions then, simplify ,50 is divided by 2 times one more than the difference of F and 3.​

Answers

Answer:

F = 27

Step-by-step explanation:

50/2 = (F - 3) + 1

25 = F - 2

F = 27

6 less than six times a number is 42 what is the number​

Answers

Answer:

x = 8

General Formulas and Concepts:

Pre-Algebra

Equality Properties

Multiplication Property of Equality Division Property of Equality Addition Property of Equality Subtraction Property of Equality

Step-by-step explanation:

Step 1: Define

Identify

6x - 6 = 42

Step 2: Solve for x

[Addition Property of Equality] Add 6 on both sides:                                    6x = 48[Division Property of Equality] Divide 6 on both sides:                                  x = 8

Answer: -6

Step-by-step explanation:

We can create an equation based on the info given.

6-6x=42 Now you solve for x, the unknown number.

-6      -6      Subtract 6 on both sides

-6x=36

/-6   /-6       Divide by -6 on both sides

x=-6

The number is -6.

yesterday kofi earned 50cedis mowing lawns. today kofi earned 60% of what he earned yesterday mowing lawns.How much did kofi earned mowing lawns today?​

Answers

Answer:

30 cedis

Step-by-step explanation:

todays earning = yesterdays earning * 60/100

50 * 60/100 =30

This answer was confusing for sure

Answers

Answer: lol ez

B.

Step-by-step explanation: XD

Answer:

D

Step-by-step explanation:

The general formula for the sine or cosine function is

y = A*Sin(Bx + C) + D

C = 0 in this case

B = pi / 3

The period is given by the formula

P = 2 * pi / B

P = 2 * pi//pi/3

The 2 pis cancel and you are left with 2*3 = 6

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