During a recent drought, a water utility in a certain town sampled 100 residential water bills and found that 75 of the residences had reduced their water consumption over that of the previous year. Find a 95% confidence interval for the proportion of residences that reduced their water consumption. Round the answers to three decimal places.

Answers

Answer 1

Answer:

The 95% confidence interval for the proportion of residences that reduced their water consumption is (0.665, 0.835).

Step-by-step explanation:

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].

Sampled 100 residential water bills and found that 75 of the residences had reduced their water consumption over that of the previous year.

This means that [tex]n = 100, \pi = \frac{75}{100} = 0.75[/tex]

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].

The lower limit of this interval is:

[tex]\pi - z\sqrt{\frac{\pi(1-\pi)}{n}} = 0.75 - 1.96\sqrt{\frac{0.75*0.25}{100}} = 0.665[/tex]

The upper limit of this interval is:

[tex]\pi + z\sqrt{\frac{\pi(1-\pi)}{n}} = 0.75 + 1.96\sqrt{\frac{0.75*0.25}{100}} = 0.835[/tex]

The 95% confidence interval for the proportion of residences that reduced their water consumption is (0.665, 0.835).


Related Questions

Brett finds 70c while doing laundry which set of coins could be the coins that Brett found

Answers

Answer:

A is the correct set of coins

An _____ is a single outcome or group of outcomes.

a.) event
b.) probability
c.) sample
d.) None of these

Answers

Answer:

D

Step-by-step explanation:

The article "an" can only be used with the word "event" so that automatically takes the choices b and c out of the way. An event is something that happens and causes the outcome, it is not the outcome, so it is not A. Thus, the answer is D


A cone has a radius of seven centimeters and height of six centimeters. Which equation correctly shows the approximate volume of the cone?

Answers

Answer: 1/3 x 3.14 x 7(2) x 6 = 308

Step-by-step explanation:

I had the same question and I got it right so there you go :)

A random sample of 300 parts was taken from a particular grinding machine. Of those parts, 12 were defective. (a) Construct a 99% upper bound for the proportion of all parts produced by this machine that will be defective. 0.0109 (b) Construct a 99% confidence interval for the proportion of all parts produced by this machine that will be defective. [ Select ] (c) It is decided that the interval produced in part (b) is too wide, and thus a new sample must be taken and a new confidence interval calculated. What sample size would be necessary to ensure that the width of the 99% confidence interval will be 0.02 or less

Answers

Answer:

a) Ub = 0,069

b)  CI 99 %  = ( 0,0287 ; 0,069 )

c) n = 2536

Step-by-step explanation:

Confidence Interval (CI) for proportion is

p₀  ±  z(c) * √ ( p₀*q₀ ) /n

Where     p₀  is the sample proportion

n = size of the sample

and z(c)   is z score for the significance level α

As    CI  = 99 %       α = 1%      α = 0,01      α/2 = 0,005

from z-table we find   z(c) = 2,57

p₀ = 12/300      p₀ = 0,04  ;    

n*p₀ = 12  > 10 and  n*q₀  = 300*0,96        n*q₀ = 288 > 10

We can use normal distribution as a valid  aproximation of binomial distibution

Then     z(c) = 2,57

a) upper bound for CI     Ub

Ub = p₀ + z(c) * √ p₀q₀/300

Ub = 0,04  +  2,57 * √ (0,04*0,96)/300

Ub = 0,04 + 0,0113

Ub = 0,069

b) CI at 99%  is

CI  = p₀  ±  z(c) * √ ( p₀*q₀ ) /n

we have already calculated the Ub = 0,069

the Lower bound would be   Lb = 0,04 - 0,0113

Lb = 0,0287

Then     CI 99 %  = ( 0,0287 ; 0,069 )

c) If      CI ≤ 0,02 we can find the minimun n value with the equation:

p₀  ±  z(c) * √ ( p₀*q₀ ) /n = CI   or    p₀  -  z(c) * √ ( p₀*q₀ ) /n = 0,01

For symmetry respect to p₀

z(c) *√ (p₀*q₀) / n  = 0,01

Solving for n

z(c) * √ ( p₀*q₀ ) /n = 0,01

2,57 * √ (0,04*0,96)/n  =  0,01

2,57 * √ 0,0384/n = 0,01

2,57 = 0,01/√ 0,0384/n

Squaring both sides of the equation

6,6049 = (0,01)² *n / 0,0384

0,0384*6,6049 / 0,0001  = n

n = 2536

Please help me solve this

Answers

Here you go. Basically you solve a quadratic equality then find the roots, values are positive when above the x axis

Confusing to me please help......

Answers

it’s 2boxes because there’s 10 in each line , with 8 rows 8x2 equals 160 which is closest to 140 .









Hi there!

[tex]\large\boxed{3 \text{ boxes}}[/tex]

Calculate the number of boxes of cubes needed by calculating the volume of the pictured figure.

We can see that it has a width of 4 blocks, depth of 2 blocks, and a height of 8 blocks.

Calculate volume: V = l × w × h

V = 4 × 2 × 8  = 64 cubes in each box.

Since she needs 140 cubes, we can find how many boxes she would need for this amount:

140 ÷ 64 = 2.1875.

However, you cannot buy a part of a box, which is why you must round to a whole number. However, only buying 2 boxes would be too little.

Thus, she would need to buy 3 boxes.

Mr. Anderson made the following box-and-whisker graph of the quiz grades in his chemistry class.


What is the median quiz grade for the class?

Answer Choices

A. 86
B. 70
C. 96
D. 77

Answers

Answer:

77

Step-by-step explanation:

I did the question and I got it correct.

What is the total of 4/7 +3/7

Answers

Answer:

7/7 also known as a whole (1)

Step-by-step explanation:

All you have to do is add 4 and 3 then keep the denominator the same (7)

For the function f(x) = 3x
Find f(4)

Answers

f(4)=3(4)
f(4)=12

Hope this helps :)

Answer:

F(4) = 3*4 = 12

Step-by-step explanation:

8m > 67
Which value of m satisfies the inequality?
A.5
B.6
C.8
D.9

Answers

Answer:

D

Step-by-step explanation:

A is wrong because 8 x 5 = 40

40 < 67

B is wrong because 8 x 6 = 30

48 < 67

C is wrong because 8 x 8 = 64

64 < 67

D is correct because 72 > 67

Hope this helps!! ♥︎

A cell phone plan charges $19.90 a month, plus $0.05 per text message

Create & solve an inequality that represents the number of texts, t, that can be

sent while still keeping the monthly bill under $25?

Answers

Answer:

[tex]19.9+0.05t<25[/tex]

Less than 102 text messages.

Step-by-step explanation:

Monthly charge of cell phone = $19.90

Cost of one text message = $0.05

Let number of text messages be [tex]t[/tex]

The monthly bill should be less than $25. So,

[tex]19.9+0.05t<25[/tex]

The required inequality is [tex]19.9+0.05t<25[/tex]

[tex]19.9+0.05t<25\\\Rightarrow 0.05t<25-19.9\\\Rightarrow t<\dfrac{5.1}{0.05}\\\Rightarrow t<102[/tex]

So, the number of text messages that can be sent while keeping the bill under $25 is less than 102.

Find the area of the parallelogram. Round to the nearest hundredth if necessary.
6 m
8 m
cm2
Area =

Answers

/// 48 cm is the area

The area of the parallelogram willl be equal to 48 square meters.

What is an area?

The space occupied by any two-dimensional figure in a plane is called the area. The parallelogram occupied by the parallelogram in a two-dimensional plane is called as the area of the parallelogram .

Given that:-

Height = 6 mBase = 8 m

The area will be calculated as:-

Area = Height  x Base

Area = 6  x  8

Area = 48 square meters.

Therefore the area of the parallelogram willl be equal to 48 square meters.

To know more about an area follow

https://brainly.com/question/25292087

#SPJ2


Amy mows 7 lawns in 4 hours. How long does it take
her to mow one lawn? Round your answer to the
hundredths place.

Answers

Answer:

0.57 hours

Explanation:

4 ÷ 7 = 0.5714285714285714

Rounded to the nearest 100th is :

0.57

Answer:

1 hour and 45 minutes

Step-by-step explanation:

I got this answer by dividing, so it takes her 1 3/4 hours which is converted to 1 hour and 45 minutes

In order to determine whether or not there is a significant difference between the mean hourly wages paid by two companies (of the same industry), the following data have been accumulated.

Company A Company B
Sample size 80 60
Sample mean $16.75 $16.25

Population standard deviation $1.00 $.95 The p-value is:_________

a. 0.0084.
b. 0.0042.
c. 0.0026.
d. 0.0013

Answers

Answer:

The p-value is;

d. 0.00131

Step-by-step explanation:

The given question parameters are;

                                                     Company A   [tex]{}[/tex]                       Company B

Sample size                                   80[tex]{}[/tex]                                         60

Sample mean   [tex]{}[/tex]                            [tex]\overline x_1[/tex] $16.75                            [tex]\overline x_2[/tex] $16.25

Population standard deviation [tex]{}[/tex]   σ₁  $1.00                           σ₂ $0.95

[tex]z=\dfrac{(\bar{x}_{1}-\bar{x}_{2})-(\mu_{1}-\mu _{2} )}{\sqrt{\dfrac{\sigma_{1}^{2} }{n_{1}}+\dfrac{\sigma _{2}^{2}}{n_{2}}}}[/tex]

Therefor, we have;

[tex]z=\dfrac{(16.75-16.25)-(0-0)}{\sqrt{\dfrac{1^{2} }{80}+\dfrac{0.95^{2}}{60}}} \approx 3.0128[/tex]

The p-value = 1 - 0.99869 (the area to the right of 3.01) = 0.00131

Can you conclude that the
parallelogram below is a
rectangle?
Yes
No

Answers

Answer:

yes

Step-by-step explanation:

Answer:

Yes. If no right angle exists, then it's not a rectangle.

Step-by-step explanation:

ТDaP is a booster shot that prevents Diphtheria, Tetanus, and Pertussis in adults and adolescents. It should be administered every 8 years in order for it to remain effective. A random sample of 500 people living in a town that experienced a pertussis outbreak this year were divided into two groups. Group 1 was made up of 132 individuals who had not had the TDaP booster in the past 8 years, and Group 2 consisted of 368 individuals who had. In Group 1, 15 individuals caught pertussis during the outbreak, and in Group 2, 11 individuals caught pertussis. Is there evidence to suggest that the proportion of individuals who caught pertussis and were not up to date on their booster shot is higher than those that were? Test at the 0.05 level of significance.
Enter the test statistic - round to 4 decimal places.
Enter the P-Value - round to 4 decimal places.
Is there evidence to suggest the proportion of those who caught pertussis is higher for those who were not up to date on their booster?

Answers

Answer: 76.8356 and 12.5372

Step-by-step explanation:

5) What does QRST → Q'R'S'T' mean?

Answers

Answer:

QRST becomes Q prime, R prime, S prime, T prime.

Step-by-step explanation:

Any figure that is rotated, translated or reflected on the corrdinate plane is considered a prime (as long as it is congruent (the same as, or equal to) with the original). The apostrophe stands for prime.

Ex. If you reflect triangle ABC across one of the axes, the original triangle will continue being ABC, while the reflection would be A' B' C' (or A prime, B prime, C prime). I hope this helps :)

The figure is a kite. The m < 1 = 125 and m < 3 = 20. Find m < 4.

Answers

m<1 + m<3/2 +m<4/2 =180

125+10 +m<4/2=180

135 +m<4/2 =180

m<4/2 =180-135

m<4/2 =45

m<4 = 90

An examination consists of multiple-choice questions, each having five possible answers. Linda estimates that she has probability 0.4 of knowing the answer to any question that may be asked. If she does not know the answer, she will guess, with conditional probability 1/5 of being correct.A. What is the probability that Linda gives the correct answer to a question? B. What is the conditional probability that Linda knows the answer, given that she supplies the correct answer?

Answers

Answer:

a. 0.52 = 52% probability that Linda gives the correct answer to a question.

b. 0.7692 = 76.92% probability that Linda knows the answer

Step-by-step explanation:

Conditional Probability

We use the conditional probability formula to solve this question. It is

[tex]P(B|A) = \frac{P(A \cap B)}{P(A)}[/tex]

In which

P(B|A) is the probability of event B happening, given that A happened.

[tex]P(A \cap B)[/tex] is the probability of both A and B happening.

P(A) is the probability of A happening.

In this question:

Event A: Supplies the correct answer:

Event B: Knows the answer

A. What is the probability that Linda gives the correct answer to a question?

0.4(knows the answer)

1/5 = 0.2 of 1 - 0.4 = 0.6(guesses the answer). So

[tex]P(A) = 0.4 + 0.2*0.6 = 0.52[/tex]

0.52 = 52% probability that Linda gives the correct answer to a question.

B. What is the conditional probability that Linda knows the answer, given that she supplies the correct answer?

Intersection of events A and B is knowing the answer and giving the correct answer, which means that [tex]P(A \cap B) = 0.4[/tex]

The desired probability is:

[tex]P(B|A) = \frac{P(A \cap B)}{P(A)} = \frac{0.4}{0.52} = 0.7692[/tex]

0.7692 = 76.92% probability that Linda knows the answer

Solve for x.
Your answer must be simplified.
17x>−17

Answers

Answer:

x>-1

Step-by-step explanation:

[tex] \frac{17}{17}x > - \frac{17}{17} \\x > - 1 [/tex]

a furniture store donated a percent of every sale to hospitals. the total sales were $8,300 so they store donated $664. what percent of $8,300 was donated to hospitals?

Answers

Answer:

8%

Step-by-step explanation:

100/8300=.01204819277

.01204819277x664=8

they donated 8% of their earnings

have a great day :D

Answer:

this is hard but it si 55 percent

Step-by-step explanation:

Write the expression in standard form.(4x - 3 + 2y) - (-4y + 2)*

Answers

Answer:

4x - 3 + 2y) - (-4y + 2) = 4x - 5 + 6y

Here. I think this is correct

Have a nice day.

ps:can you do me the brainliest.

A baseball player throws a ball from second base to home plate. How far does the player throw the ball? Include a diagram showing how you got your answer. Decide how many decimal points of accuracy are reasonable. Explain your reasoning.

Answers

Answer:

127 ft 3 3/8in

Step-by-step explanation:

Assuming the field is regulation (I can't see the model), the answer is 127 feet and 3 3/8 inches.

What is the answer to -20=p/15

Answers

Answer:

Solve for p by simplifying both sides of the equation, then isolating the variable.

p = − 300

Step-by-step explanation:

have a nice day

I think p=300???

Sorry if thiz is wrong. i dont really know that much

A rectangle with length n and height m. A right triangle with hypotenuse n + 1, length n, and height m.
The perimeter of the rectangle is 34 cm. The perimeter of the triangle is 30 cm. Find the value of n.

Please select the best answer from the choices provided

A. 10cm
B. 14cm
C. 12cm
D. 16cm

Answers

9514 1404 393

Answer:

  C. 12cm

Step-by-step explanation:

The equation for the perimeter of the rectangle is ...

  P = 2(L+W)

  34 = 2(n +m)

Solving for m, we get

  m = 17 -n . . . . . . . divide by 2, subtract n

__

The Pythagorean theorem gives the relationship between the sides and the hypotenuse

  m^2 +n^2 = (n+1)^2

  (17 -n)^2 +n^2 = (n +1)^2 . . . . . . substitute for m

  289 -34n +n^2 +n^2 = n^2 +2n +1 . . . . eliminate parentheses

  n^2 -36n +288 = 0 . . . . . . . put in standard form

  (n -12)(n -24) = 0 . . . . . . . . . factor

  n = 12 . . . . . . . . . . n=24 is an extraneous solution here

The value of n is 12 cm.

Answer:

12 cm. Just took the quiz! 12 is the right answer not 14 cm.

Step-by-step explanation:

What is the length of BC?

Answers

Answer:

Step-by-step explanation:

Since AC and AB are opposite equal angles AC=AB

2x-24=x-2

x=22

So BC=x=22

So it would be BC equals X equals 22 oh and you don’t have to tell me thank you cause you’re welcome

Find two numbers such that their sum, their difference, and their product have the ratio 3:2:5.​

Answers

Answer:

2 and 10

Step-by-step explanation:

We will assume to numbers represented by x and y.

From the question, we can write the following :

sum = x + y

difference = x - y

product = xy or x*y

Since we have two unknowns, general rule of thumb is that we require

2 equations to solve for them.

Using the ratio, of  sum:  difference and sum : product,

I can form these 2 equations:

(x + y) / (x -y) = 3/2  (1)

(x + y) / (x*y) = 3/5 (2)

In (1),

we cross multiply and do some tidying we will get

x = 5y

In (2),

we have 5x + 5y = 3x*y

We can then substitute x = 5y into (2) and get the following

5*5y + 5y = 3*5y*y

30y = 15y^2

2y = y^2

y^2 - 2y = 0

After factorization,

y(y - 2) = 0

you will have to options either use y = 0 or y = 2

If we use 2, then using equation (1),

we can solve for x which is 10.

Answer:

2 , 10

Step-by-step explanation:

(x+y) / (x-y) = 3/2   ..(1)

3x-3y = 2x+2y

x = 5y

(x+y) / xy = 3/5

(5y+y) / (5y*y) = 3/5

6y/5y² = 3/5

15y² = 30y

y = 2

x = 10

check: (2+10) : (10-2) : (10*2) = 12 : 8 : 20 = 3 : 2 : 5

I need a expert or anyone that is smart to answer this I’m offering a brainalist + 25 points

Answers

Answer:

B im pretty sure!!

Step-by-step explanation:

Definition of Complementary and Supplementary Angles Complementary angles are two angles that add to 90 degrees. Supplementary are two angles that add to 180 degrees.

Which answer best describes the shape of this distribution?


uniform

skewed left

bell-shaped

skewed right
An untitled line plot from 35 to 49. The plot displays the following values as dots above the corresponding value on the number line. One dot at 36. One dot at 37. One dot at 38. One dot at 40. Two dots at 41. One dot at 42. Three dots at 43. Four dots at 44. Five dots at 45. Three dots at 46. Two dots at 47. One dot at 48.

Answers

Answer:

huh what am i looking at

Step-by-step explanation:

step-by-step explanation

Answer:

its skewed left if you are in k12

Step-by-step explanation:

answer ty ill give brainliest.

Answers

Answer:

5

Step-by-step explanation:

to get from 5 to 1 you divide by 5 that is how you get the scale factor

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