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 variance is 1.69 gallons and the mean is 15.9 gallons per day. If they are using a 85% level of confidence, how large of a sample is required to estimate the mean usage of water? Round your answer up to the next integer.

Answers

Answer 1

Answer:

A sample of 179 is needed.

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 - 0.85}{2} = 0.075[/tex]

Now, we have to find z in the Ztable as such z has a pvalue of [tex]1 - \alpha[/tex].

That is z with a pvalue of [tex]1 - 0.075 = 0.925[/tex], so Z = 1.44.

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.

A previous study found that for an average family the variance is 1.69 gallon?

This means that [tex]\sigma = \sqrt{1.69} = 1.3[/tex]

If they are using a 85% level of confidence, how large of a sample is required to estimate the mean usage of water?

A sample of n is needed, and n is found for M = 0.14. So

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

[tex]0.14 = 1.44\frac{1.3}{\sqrt{n}}[/tex]

[tex]0.14\sqrt{n} = 1.44*1.3[/tex]

[tex]\sqrt{n} = \frac{1.44*1.3}{0.14}[/tex]

[tex](\sqrt{n})^2 = (\frac{1.44*1.3}{0.14})^2[/tex]

[tex]n = 178.8[/tex]

Rounding up

A sample of 179 is needed.


Related Questions

Can someone please help me with this!

Answers

Answer:

It's Positive

Step-by-step explanation:

PLEASE HELP ASAP REAL ANSWERS ONLY OR WILL BE DELETED! 20 PTS!!

Find the height in centimeters of a square pyramid with a volume of 296 cm3 and a base edge length equal to the height. Give the approximate answer rounded to 2 decimal places.

Answers

Answer:

9.61cm

Step-by-step explanation:

Let height be x thus length will also be x

since the base is a square the width and length are also equal.

volume of pyramid=length×width×height

3

296cm³=x×x×x

3

296×3=x³

888=x³

x= cube root of 888

x=9.61cm

what is is distance between (0,2) and (5,2)

Answers

5 units. The only variable changing is x so it's just 5 units up from the second coordinate

Pls answer just the answer

Answers

Answer:

588000

Step-by-step explanation:

if i am wrong pls tell me cause i think there's a different answer gl g

Answer:

$103,421.88

Step-by-step explanation:

Given:

P = 70000

r = 0.05

n = 1

t = 8

Work:

[tex]A=P(1+\frac{r}{n} )^{nt}\\\\A=70000(1+\frac{0.05}{1} )^{1*8}\\\\A=70000(1.05)^8\\\\A=103421.88[/tex]

Find the mean absolute deviation for the set below. S = 65, 90, 85, 70, 70, 95, 55
A. 12.24
B. 75.7
C. 114
D. 32.67
(I’ll give points + brainalist)

Answers

Answer:

A) 12.24

Step-by-step explanation:

Mean absolute deviation: 65, 90, 85, 70, 70, 95, 55 = 12.244897959184

Answer:

75.7

Step-by-step explanation:

what is 81 divided by 9​

Answers

Answer:

9

Step-by-step explanation:

9

9x9 = 81

Therefore, 81 ÷ 9 is 9

kengrew 4/5 of an inch last year sang grew three eighths of an inch who grew more and by how much ​

Answers

Answer:

Ken;

Step-by-step explanation:

Ken grew 4/5 of an inch. 4/5=0.8

Sang grew 3/8 of an inch. 3/8= 0.375

0.8 > 0.375 so Ken grew more.

0.8 - 0.375 = 0.425

So, Ken grew 0.425 more inches than Sang grew. 0.425 is also the same thing as 17/40.

help please i need it asap

Answers

The correct answer would be 6

A can of juice has a radius of 4 inches and a height of 7 inches. What is the volume of the can?
Round your answer to the nearest tenths place.

Answers

Answer:

351.7

Step-by-step explanation:

Volume of a cylinder:

V = πr²h

V = 3.14(4²)(7)

V = 3.14(16)(7)

V = 50.24(7)

V = 351.68

Rounded to the nearest tenth:

351.7

5. Consider the contexts the follow.
a. Create a table for each context.
b. Graph the data in each table.
c. Determine a recursive rule then an explicit equation that fits each context.

Context D: The Rowing Team is selling cookies for $1 each. A friend is selling the cookies and allows you to pay later for cookies you buy beyond the $3 you have in your pocket. How much will you pay your friend if you buy C cookies? (Negative dollars are dollars you pay your friend after the sale).

Answers

Answer:

d

Step-by-step explanation:

1+3=4

what property is 8 • 1 and 8

Answers

Ans: A. Additive Identity Property.
Are you talking about 8 x 1 = 8? The property is called the Identity property of 1 or the Multiplicative Property of 1. It states that X(1)=x; anything times 1 will always be 1.


On a flight,
3/10
of the passengers were children. There were
60 children on the flight. How many passengers were on
the plane?

Answers

Answer:

There were 200 passengers on the plane.

Step-by-step explanation:

1. 3/10  of the passengers were children -> 30% of the passengers were children

2. 60 children on the flight 30% of passengers = 60 people

divide by 3 -> 10% of passengers = 20 people

multiply by 10 -> 100% of passengers = 200 people.

Four roommates want to split the price of a computer. How much will each roommate pay? Write an equation and solve it by using the information in the table.
A 2-column table with 4 rows. Column 1 is labeled Electronics with entries Mp3 player, computer, tablet, smart phone. Column 2 is labeled Sale Price in dollars with entries 39, 299, 199, 78.


$49.75
$74.75
$156
$1196
Mark this and return Four roommates want to split the price of a computer. How much will each roommate pay? Write an equation and solve it by using the information in the table.


A 2-column table with 4 rows. Column 1 is labeled Electronics with entries Mp3 player, computer, tablet, smart phone. Column 2 is labeled Sale Price in dollars with entries 39, 299, 199, 78.


$49.75
$74.75
$156
$1196
Mark this and return Four roommates want to split the price of a computer. How much will each roommate pay? Write an equation and solve it by using the information in the table.


A 2-column table with 4 rows. Column 1 is labeled Electronics with entries Mp3 player, computer, tablet, smart phone. Column 2 is labeled Sale Price in dollars with entries 39, 299, 199, 78.


$49.75
$74.75
$156
$1196
Mark this and return Four roommates want to split the price of a computer. How much will each roommate pay? Write an equation and solve it by using the information in the table.


A 2-column table with 4 rows. Column 1 is labeled Electronics with entries Mp3 player, computer, tablet, smart phone. Column 2 is labeled Sale Price in dollars with entries 39, 299, 199, 78.
Four roommates want to split the price of a computer. How much will each roommate pay? Write an equation and solve it by using the information in the table.


A 2-column table with 4 rows. Column 1 is labeled Electronics with entries Mp3 player, computer, tablet, smart phone. Column 2 is labeled Sale Price in dollars with entries 39, 299, 199, 78.


$49.75
$74.75
$156
$1196
Mark this and return
$49.75
$74.75
$156
$1196
Mark this and return
$49.75
$74.75
$156
$1196
Mark this and return

Answers

Answer: $74.75

Step-by-step explanation:

Answer:

74.75 dolors i take test

Step-by-step explanation:

Priscilla makes a profit of $24.50 on every scarf she sells the materials for each scarf cost $8.39 how much does Priscilla sell each scarf for?

Answers

Answer:

SP = $32.89

Step-by-step explanation:

Given that,

CP of every scarf = $8.39

Profit = $24.50

We need to find the SP for each scarf. We can find it as follows :

SP = CP +profit

SP = 8.39+24.50

SP = $32.89

So, Priscilla sells each scarf for $32.89.

these questions seem harder than usual im sorry for the bother

Answers

the answer is the first one

Answer:

A

Step-by-step explanation:

Which category do both of these shapes belong to

Answers

Answer:

D. Parallelogram

Step-by-step explanation:

Answer:

The answer is Parallelgram(D)

two pairs of parallel sides in a quadrilateral

hope it helps...

Identify the terminal point for a 45° angle in a unit circle.

Answers

9514 1404 393

Answer:

  (x, y) = ((√2)/2, (√2)/2))

Step-by-step explanation:

See the attached chart. The 45° angle can be found in the upper-right portion of the chart (1st quadrant).

Which two statements are true according to the law of supply? A decrease in demand leads to an increase in supply. A decrease in demand leads to a decrease in supply. There is no change in demand or supply. A decrease in price leads to a decrease in supply. An increase in price leads to an increase in supply.

subject is economics

Answers

Answer:

b and c

Step-by-step explanation:

a decrease in demand leads to a decrease in supply. and if there is no change in demand or supply.

For what values of x is the perimeter of the figure greater than 112 ​meters?

Select the correct choice below and fill in the answer box to complete your choice.

Answers

Answer:

John is buying shirts for his softball team.  He will pay a one-time processing fee of $27.50 and $12.75 per each shirt ordered.  Which equation can be used to find y, the total cost to buy xshirts? John is buying shirts for his softball team.  He will pay a one-time processing fee of $27.50 and $12.75 per each shirt ordered.  Which equation can be used to find y, the total cost to buy xshirts? John is buying shirts for his softball team.  He will pay a one-time processing fee of $27.50 and $12.75 per each shirt ordered.  Which equation can be used to find y, the total cost to buy xshirts? vv

Step-by-step explanation:

base 44 percentage 99

Answers

do you have to round to anything

Please help I’ll mark you as brainliest if correct!

Answers

Answer:

oh, easy it’s 25:)

Step-by-step explanation:

What is the answer to 1+1 ?​

Answers

Answer:

2

Step-by-step explanation:

1+1=2

Thank you for coming to my TED Talk

Answer:

22

Step-by-step explanation:

10. Find the surface area of the triangular prism. The
base of the prism is an isosceles triangle.
48 cm
25 cm
24 cm
14 cm

Answers

Answer:

C

Step-by-step explanation:

The surface area can be found through the formula

SA=2A+(a+b+c)h

in this case, A is the area of the base, a and b are the legs, c is the base of the triangle, and h is the height. By substituting the values 25 and 25 for the legs and 14 for the base and 48 for the height, you will get 3408 sq cm.

which expression can you substitute for x in 5x+y=8 to solve the system below?
5x+y=8
x+4y=2

Answers

Answer:

x =30/19 and y =2/19

Step-by-step explanation:

5x + y = 8

x + 4y = 2

then

5x + y = 8

-5(x +4y =2)

5x + y = 8

-5x - 20y = - 10

0 +y - 20y = -2

- 19y = -2

y = 2/19 then

5x + 2/19 = 8

5x = 152-2/19

5x/5 =150/19 *1/5

x =30/19

Find the 70th term of the arithmetic sequence 29, 17, 5

Answers

Answer:

857

Step-by-step explanation:

70th term = a + d(n-1)

d= 29-17=12

a=29

n-1 = 69

70th term = 29 + 12×69

= 29 + 828

= 857

a1=-3, r= -3, n = 10

Answers

Answer:

N =10

Step-by-step explanation:

N = 10 A1=3
R=-3 hhhhhhhgh

2(20 - 3x) = x
[tex]ax {}^{2} + bx + c = 0[/tex]

Answers

Answer:

                   

Step-by-step explanation:

                                                                         

Find an equation of the line with the given slope that passes through the given point. Write the equation in the form Ax + By = C.

m = 4, (6,6)

Answers

Answer:

[tex]4x-y=18[/tex]

Step-by-step explanation:

We want to find the equation of a line in standard form with a slope of 4 and passes through the point (6, 6).

First, we can write it in point-slope form. Point-slope form is given by:

[tex]y-y_1=m\left(x-x_1\right)[/tex]

Where (x₁, y₁) is a point and m is the slope.

Substitute:

[tex]y-6=4(x-6)[/tex]

Distribute the right:

[tex]y-6=4x-24[/tex]

Now, we can separate all the variables and the constants. Subtract 4x from both sides:

[tex]-4x+y-6=-24[/tex]

Add add 6 to both sides:

[tex]-4x+y=-18[/tex]

Traditionally, A or the coefficient of x is always positive. Hence, we can divide both sides by -1 to acquire:

[tex]4x-y=18[/tex]

To a set of five grades with an average of 7.31, the following grades are added 4.47 and 9.15 What is the new average?

Answers

Answer:

New mean average of 7 grades = 7.17 (Approx.)

Step-by-step explanation:

Given:

Mean average of 5 grades = 7.31

Number of grades = 5

New grades = 4.47 and 9.15

Find:

New mean average of 7 grades

Computation:

Total of old grades = Mean average of 5 grades x Number of grades

Total of old grades = 7.31 x 5

Total of old grades = 36.55

Total of new grades = Total of old grades + 4.47 + 9.15

Total of new grades = 36.55 + 4.47 + 9.15

Total of new grades = 50.17

New mean average of 7 grades = 50.17 / 7

New mean average of 7 grades = 7.167

New mean average of 7 grades = 7.17 (Approx.)

michaela spent $33 on 3 rose bushes and 3 pots of ivy. totsakan spent $92 on 12 rose bushes and 4 pots of ivy. find the cost of one rose bush and the cost of one pot of ivy​

Answers

Answer:

One rose bush costs $6

One pot of ivy costs $5

Step-by-step explanation:

Set up an equation:

Variable x = cost of rose bushes

Variable y = cost of pots of ivy

3x + 3y = 33

12x + 4y = 92

I will use substitution to first solve for x:

3y = 33 - 3x

Divide both sides by 3

y = 11 - x

Substitute y value for 11 - x:

12x + 4(11 - x) = 92

Use distributive property

12x + 44 - 4x = 92

Combine like terms

8x + 44 = 92

8x = 48

Divide both sides by 8

x = 6

Solve for y by plugging in 6 for the x value:

3(6) + 3y = 33

18 + 3y = 33

3y = 15

Divide both sides by 3

y = 5

Check work:

3(6) + 3(5) = 33

18 + 15 = 33

33 = 33

Correct

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