In a sample of 42 water specimens taken from a construction site, 26 contained detectable levels of lead. Construct a 95% condence interval for the proportion of water specimens that contain detectable levels of lead

Answers

Answer 1

Answer:

The 95% confidence interval for the proportion of water specimens that contain detectable levels of lead is (0.472,0.766).

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].

In a sample of 42 water specimens taken from a construction site, 26 contained detectable levels of lead.

This means that [tex]n = 42, \pi = \frac{26}{42} = 0.619[/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}} = 0.619 - 1.96\sqrt{\frac{0.619*0.381}{42}} = 0.472[/tex]

The upper limit of this interval is:

[tex]\pi + z\sqrt{\frac{\pi(1-\pi)}{n}} = 0.619 + 1.96\sqrt{\frac{0.619*0.381}{42}} = 0.766[/tex]

The 95% confidence interval for the proportion of water specimens that contain detectable levels of lead is (0.472,0.766).


Related Questions

An amount of $32,000 is borrowed for 10 years at 5.75% Interest, compounded annually. If the loan is paid in full at the end of that period, how much must be
paid back?
Use the calculator provided and round your answer to the nearest dollar.
5
?

Answers

Answer:

Total cost of the loan $55,969.8.-

Step-by-step explanation:

Giving the following information:

An amount of $32,000 is borrowed for 10 years at 5.75% Interest, compounded annually.

To calculate the total cost of the loan, we need to use the Future Value (FV) formula:

FV= PV*(1 + i)^n

PV= loan

i= interest rate

n= number of periods

FV= 32,000*(1.0575^10)

FV= $55,969.8

You have just gotten your first job. You have decided you want to take your parents out for dinner to celebrate and you have anticipated it will cost approximately $120 for the three of you to go out for dinner. At your job, you make an hourly wage of $11. How many hours would you need to work to pay for the dinner? What if you wanted to add a 15% tip? Could your strategy also allow you to find out how much money you made for any number of hours?

Answers

Answer:

I will have to work 11 hours to take my parents to a $ 120 cost dinner, and I will have $ 1 left in return.

If I wanted to tip 15%, I would have to work 13 hours and have $ 5 left over.

In turn, to determine the money generated from an indeterminate number of hours worked, the applicable formula would be 11X = Y, where Y is the money generated and X is the number of hours worked.

Step-by-step explanation:

Since I have just gotten my first job, and I have decided I want to take my parents out for dinner to celebrate and I have anticipated it will cost approximately $ 120 for the three of us to go out for dinner, and at my job, I make an hourly wage of $ 11, to determine how many hours would I need to work to pay for the dinner, and what if I wanted to add a 15% tip, and determine if my strategy could also allow me to find out how much money and or made for any number of hours, the following calculations must be performed:

120/11 = X

10.9 = X

11 x 11 = 121

Therefore, I will have to work 11 hours to take my parents to a $ 120 cost dinner, and I will have $ 1 left in return.

(120 x 1.15) / 11 = X

138/11 = X

12.54 = X

11 x 13 = 143

Therefore, if I wanted to tip 15%, I would have to work 13 hours and have $ 5 left over.

In turn, to determine the money generated from an indeterminate number of hours worked, the applicable formula would be 11X = Y, where Y is the money generated and X is the number of hours worked.

Is 3.37 less than 3.368

Answers

Answer:

no

Step-by-step explanation:

Answer:

it's not

Step-by-step explanation:

The average zinc concentration recovered from a sample of measurements taken in 36 different locations in a river is found to be 2.6 grams per milliliter. Find the 95% and 99% confidence intervals for the mean zinc concentration in the river. Assume that the population standard deviation is 0.3 gram per milliliter.

Answers

Answer:

The 95% confidence interval for the mean zinc concentration in the river is between 1.75 and 3.45 grams per milliliter.

The 99% confidence interval for the mean zinc concentration in the river is between 1.48 and 3.72 grams per milliliter.

Step-by-step explanation:

95% confidence interval:

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 Ztable as such z has a pvalue 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.

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

[tex]M = 1.96\frac{2.6}{\sqrt{36}}[/tex]

[tex]M = 0.85[/tex]

The lower end of the interval is the sample mean subtracted by M. So it is 2.6 - 0.85 = 1.75 grams per milliliter.

The upper end of the interval is the sample mean added to M. So it is 2.6 + 0.85 = 3.45 grams per milliliter.

The 95% confidence interval for the mean zinc concentration in the river is between 1.75 and 3.45 grams per milliliter.

99% confidence level:

By the same logic as for the 95% confidence interval, we have that [tex]Z = 2.575[/tex]. So

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

[tex]M = 2.575\frac{2.6}{\sqrt{36}}[/tex]

[tex]M = 1.12[/tex]

The lower end of the interval is the sample mean subtracted by M. So it is 2.6 - 1.12 = 1.48 grams per milliliter.

The upper end of the interval is the sample mean added to M. So it is 2.6 + 1.12 = 3.72 grams per milliliter.

The 99% confidence interval for the mean zinc concentration in the river is between 1.48 and 3.72 grams per milliliter.

4 quarts= how many gallons

Answers

4 quarts would equal one gallon

If f(x)= 1/x+2 and a>3, which of the following could be f(a)
A =1/2
B = 1/3
C = 1/4
D = 1/6

Answers

The equivalent value of the function is f ( a ) = ( 1/6 ) , when a > 3

Given data ,

Let the function be represented as f ( x )

Now , the value of f ( x ) is

f ( x ) = 1 / ( x + 2 )

Now , the value of x > 3

So , the value of f ( x ) = f ( a )

And , when x > 3

f ( 4 ) = 1 / ( 4 + 2 )

f ( 4 ) = 1 / 6

Hence , the function is f ( 4 ) = 1 / 6

To learn more about function rule click :

https://brainly.com/question/3760195

#SPJ1

A sample of 64 observations has been selected to test whether the population mean is smaller than 15. The sample showed an average of 14.5 and a standard deviation of 4.7. You want to test this hypothesis at 95% level of confidence using the critical value approach. First, compute the critical value and the test statistics associated with this test. Second, compute the difference between the test statistic and the critical value (test statistic - critical value). What is this difference

Answers

Answer:

Test statistic = - 0.851063

- 2.520463

Step-by-step explanation:

H0 : μ ≥ 15

H1 : μ < 15

Sample mean, xbar = 14.5

Sample standard deviation, s = 4.7

Sample size = 64

Teat statistic :

(xbar - μ) ÷ (s/√(n))

(14.5 - 15) ÷ (4.7/√(64))

= - 0.851063

The critical value at α = 0.05

Using the T - distribution :

Degree of freedom, df = 64 - 1 = 63

Tcritical(0.05, 63) = 1.6694

Test statistic - critical value

-0.851063 - 1.6694

= - 2.520463

Find the area of a semi-circle that has a radius of 8 cm.



image

A.
100.48 cm2

B.
200.96 cm2

C.
50.24 cm2

D.
25.12 cm2

Answers

Answer:

A

Step-by-step explanation:

trust

Answer:

B.

200.96 cm2

Step-by-step explanation:

A≈201.06cm²

Solution

A=πr2=π·82≈201.06193cm²

Jennifer has a collection of 1,600 coins. Of the coins, 40% are dated before 1940, 35% are dated from 1940 to 1980, and the rest are dated after 1980. How many coins in Jennifer’s collection are dated after 1980?

Answers

Answer:

Step-by-step explanation:

 40% + 35 % = 80 %    so 20% are dated after 1980

20% is .20 in decimal form

.20 (1600) = 320 coins dated after 1980

 

Can someone help me really please

Answers

Answer:

Step-by-step explanation:

question

Answer:

the tank at the pet store

Step-by-step explanation:

5x4x2 = 40

35<40

What is equavalent 3 11/40.
The best estimate close to this answer 3 11/40
A. 2 1/2
B. 3 Plzz help me
C. 3 1/2
D. 4

Answers

Answer:

C. 3 1/2

Step-by-step explanation:

Estimate the fraction part of the number.

11/40 > 10/40 = 1/4

We can estimate the fraction part as 1/2 since its greater than 1/4.

The number becomes 3 1/2.

Best choice is C

Answer:

11/40>10/40=1/4 is a part of ½

so

best estimate is 3 ½.

Solve the following system of equations:
x+2y=-4
x-2y=8

Answers

Answer:

x=2   y=-3

Step-by-step explanation:

We first need to isolate x to get x+2y=-4:x=-4-2y

-4-2y-2y=8

simplify:

-4-4y=8.

We can also do the same for y which is -4-4y=8:y=-3

for the x, we can now substitute it to give us:

x=-4-2(-3)

-4-2(-3)=2

x=2

So, our answers are x=2 and y=-3

Answer:

Step-by-step explanation:

x+2y=-4

x-2y=8                       Add

2x = 4                        Divide by 2

2x/2 = 4/2

x = 2

x + 2y = - 4                Substitute 2 for x

2 + 2y = - 4               Subtract 2 from both sides

2y = - 4 - 2

2y = - 6                     Divide by 2

2y/2 = - 6/2

y = - 3

HELP PLEASE!!
Explain the error in the following exercise;
then correct it.

Answers

Answer:

2/1x7/6=14/6=7/3

Step-by-step explanation:

Multiply the 2 by the 7 but Not the 6. So the second number is 14/6, not 14/12.

‘Then simplify 14/6 to 7/3

x plus 1 > 3

The souliton is

Answers

Answer:

x > 2

Step-by-step explanation:

x + 1 > 3

Subtract 1 from both sides

x + 1 - 1 > 3 - 1

x > 2

How many cubes with side lengths of 1/4 cm does it take to fill the prism?

Answers

Step-by-step explanation:

All you do is add them all up but tbh that picture could use some work and maybe when you fix it ill help you then .So the square unit of this picture is 6

100 points
(algebra one)
describe and correct the error in comparing the graphs

Answers

Answer:

The error made is that the graph of [tex]y=x^{2} +3[/tex] is a vertical translation up by 3, instead of down.

Step-by-step explanation:

Exponential functions, when they are graphed, use the function [tex]f(x)=a(x-h)^{2} +k[/tex].

In the equation, k expresses how much the graph shifts vertically. In this case, the function shifts vertically up by 3 from the parent function, [tex]y=x^{2}[/tex]. So, the translation is actually 3 units up compared to the graph of [tex]y=x^{2}[/tex].

Hope this helps and have an amazing day!! ❤

The measure of an angle is 89. Find the measure of its supplement
a. 91
b. 89
c. 90
d. 80

Answers

Answer:

A. 91

Step-by-step explanation:

Supplementary angles are 2 angles that when added together, equal 180 degrees. 91+89=180

Hope this helps. here are free cookies --->

The data are from a small moving company that moves people from urban apartment buildings to other urban apartment building in the same or different cities. The company needs assistance in predicting the labor hours for jobs so they can provide more accurate price quotes.
Run two separate regressions using the data in the sections of the spreadsheet titled Regression Model 1 and Regression Model 2. Use a 95% confidence level.
Fill in all the blanks below. Do not round any numbers except for when entering them in the blanks for this quiz, round these numbers to exactly 2 decimal places even if the number has only one or no decimal places. Use commas to separate thousands (e.g., 1225 should be entered as 1,225.00).
Regression Model 1
R Square expressed as a percentage rounded and carried out to two decimal places is ________% and Adjusted R Square expressed as a percentage rounded and carried out to two decimal places is _______%. Refer to the spreadsheet embedded in your Module 14 Regression document I provided you to see the calculation and format for answering this next question. The gap between R Square and Adjusted R Square expressed as a percentage rounded and carried out to two decimal places is 0.______%.
The overall regression model (was / was not) _______ significant.
Using square footage of 1,500 and mileage of 92, the model estimates that ______ hours of labor would be required, with a margin of error of _________ hours.
Regression Model 2
R Square expressed as a percentage rounded and carried out to two decimal places is _______% and Adjusted R Square expressed as a percentage rounded and carried out to two decimal places is _______%. Refer to the spreadsheet embedded in your Module 14 Regression document I provided you to see the calculation and format for answering this next question. The gap between R Square and Adjusted R Square expressed as a percentage rounded and carried out to two decimal places is 0.________%.
The overall regression model (was / was not) __________ significant.
Using square footage of 1,500, mileage of 92, and floors of 71, the model estimates that _________ hours of labor would be required, with a margin of error of ________ hours.
Model Selection
Because the R Square is (higher / lower) _________ in regression model 1 than in regression model 2 and the gap between R Square and Adjusted R Square is (smaller / larger) in regression model 1 than in regression model 2 _________ and the margin of error of the estimated labor hours is (smaller / larger) _________ in regression model 1 than in regression model 2 , we would characterize regression model (1 or 2) ___________ as being the better model.


Answers

Answer:

I wish I can read all the text

Plz help me well mark brainliest if correct................?

Answers

Answer:

B. 8cm*12cm

Step-by-step explanation:

Area is the product of the two sides:

6*16 = 96

8*12 = 96

10*10 = 100

Perimeter is the sum of all four sides:

6+16+6+16 = 44

8+12+8+12 = 40

The answer is B. 8cm*12cm

It’s B 8x12 is equal to 96

Describe how to graph the solution of y ≤ −x2 + 2x.

Answers

Answer:

See graph and explanation

Step-by-step explanation:

Assuming you mean y ≤ −x² + 2x, you graph y = −x² + 2x and then fill in the area beneath the curve of the parabola to represent the included values. See the graph for a visual.

Plsss help. giving extra points if correct.

Answers

Answer:

C

Explanation:

I think it’s C because the two triangles you are comparing are both in the exterior of the lines.
C I’m not sure but I think it is

Plsss help will give brainlest no links or files plss

Answers

Answer:

1: 62

2: 118

3: 62

4: 118

Step-by-step explanation:

1 and 3 are opposite angles so they have the same measure. 2 and 1 are adjacent angles on a linear plane. since a line is 180 degrees and we know that one of the angles on this plane is 62, that means that angle 2 must be 180 - 62 which 118 degrees

please find the value of X for number 4 5 and 6 thank you :)

Answers

Answer:

4. x = 6

5. x = 31

6. x = 34

Step-by-step explanation:

4. vertical angles

- 36/6 = 6

5. supplementary angles

180 - 56 = 124

124/4 = 31

6. complementary angle

90 - 22 = 68

68/2 = 34

Answer:

4. x = 6°

5. x = 31°

6. x = 34°

Step-by-step explanation:

4. Vertical Angles theorem states that the two opposite angles formed by 2 intersecting lines are congruent.

6x = 36°

x = 36 / 6

x = 6°

5.

180° - 56° = 4x

124° = 4x

x = 31°

6.

90° - 22° = 2x

68° = 2x

x = 34°

If my answer is incorrect, pls correct me!

If you like my answer and explanation, mark me as brainliest!

-Chetan K

A random sample of 11 fields of rye has a mean yield of 20.1 bushels per acre and standard deviation of 7.66 bushels per acre. Determine the 80% confidence interval for the true mean yield. Assume the population is approximately normal. Round your answer to one decimal place.

Answers

Answer:

17.1≤x≤23.1

Step-by-step explanation:

The formula for calculating the confidence interval is expressed as;

CI = x ± z*s/√n

x is the mean yield = 20.1

z is the 80% z-score = 1.282

s is the standard deviation = 7.66

n is the sample size =  11

Substitute

CI = 20.1 ± 1.282*7.66/√11

CI = 20.1 ± 1.282*7.66/3.3166

CI = 20.1 ± 1.282*2.3095

CI =  20.1 ±2.9609

CI = (20.1-2.9609, 20.1+2.9609)

CI = (17.139, 23.0609)

hence the required confidence interval to 1dp is 17.1≤x≤23.1

An office building is 18 meters high. What
calculation would convert its height to
yards? Use 1 meters = 1.09 yards.

Answers

Answer:

19.62 yards

Step-by-step explanation:

18 x 1.09 = 19.62

Practice:

Determine the coordinates of the point on the unit circle corresponding to the given central angle. If necessary, round your results to the nearest hundredth.
180°

a. (-1, 0)
b. (0, 1)
c. (0, -1)
d. (1, 0)

Please select the best answer from the choices provided

Answers

Answer:

A. (-1, 0)

Step-by-step explanation:

I calculated it logically

hello if anyone would pls help

Answers

Answer:

x = 12

Step-by-step explanation:

It is a 90° angle which means that both of the angles need to add up to 90. 90-20 =70. 6×12 = 72.

6×9= 72

72-2 = 70

It adds up.

Hope this helps.

A 6-sided die with sides numbered 1 through 6 is tossed. A penny is then tossed. If the penny comes up heads, the value of the die is multiplied by 2. Otherwise, the value of the die is left unchanged.

What is the probability that the outcome is less than 6?

Answers

Answer:

The probability that the outcome is less than 6 is 58.333%.

Step-by-step explanation:

Since a 6-sided die with sides numbered 1 through 6 is tossed, ya penny is then tossed, and if the penny comes up heads, the value of the die is multiplied by 2, but otherwise, the value of the die is left unchanged, to determine what is the probability that the outcome is less than 6 the following calculation must be performed:

(5/6 + 2/6) / 2 = X

(0.8333 + 0.0333) / 2 = X

1.1666666 / 2 = X

0.583333 = X

Therefore, the probability that the outcome is less than 6 is 58.333%.

A pack of 4 chocolate bars costs £1.20
What is the price per unit?



what is it?

Answers

Answer:

0.30 you divided the total by the number of units which is 4

Answer:

£ 0.3

Step-by-step explanation:

Given that , a pack of 4 chocolates costs £1.20. We need to find cost of one chocolate .

We can simply use Unitary Method here ,as ,

=> 4 chocolates costs £1.20 .

=> 1 chocolate will cost £1.20/4 = £ 0.3

Hence the cost of unit is £ 0.3

The difference of x and y is the same as 3 times the sum of x and 2

Answers

Answer:

x - y = 3(x + 2)

x - y = 3x + 6 is the simplified answer and is also correct

Step-by-step explanation:

The difference of x and y is the same as 3 times the sum of x and 2

x - y = 3(x + 2)

x - y = 3x + 6

Answer:

spoke out of term and with no true option.

Other Questions
____is the amount of matter in an object and is measured in kilograms.A. MassB. GravityC. NewtonD. Weight The bear climbs up the tree. The bear is brown. The bear is large. It is a grizzly bear. Into one sentence Use the figure to answer the question. 8 8 What is the area of the shaded region of the circle in terms of a? Enter the answer in the box. The area of the shaded region is f units squared. The perimeter of a square is 36 centimeters.What is the length of the diagonal of the square?62 cm92 cm122 cm182 cm 4. Your best friend's birthday is tomorrow, and you would like to give her an ice cream coneballoon. The spherical shaped ice cream on top of the cone has a radius of 6 inches. The coneitself has a diameter of 12 inches and height of 24 inches. How many cubic inches of helium arended to fill the entire ice cream cone balloon? Use 3.14 for it. 4x-2 x=5can someone help me with this? What is the standard angle of a reference angle of 30 in Quadrant III?A. 210 degreesB. 225 degreesC. 150 degreesD. 240 degrees What was the cause of the Wilmington Riots?A. Republicans wanted to show their anger after losing the 1898 state election.B. Republicans wanted to take control of the Democratic-led Wilmington government.C. Democrats wanted to take control of the Republican-led Wilmington government.D. Democrats wanted to retaliate against white supremacists. an example of an atmospheric beauty that occurs in the thermosphere? i need help with french pleaseeeeeeee A square has an area of 16 square ft what would be the measurement of its side what is the HCF of 3000 and 525 answer with process Need help with school REWARDING BRAINLIEST IF YOU DONT GET IT LMK IF YOU WANT ME TO MAKE A POST (you have to be early) OR TRY AND LOOK FOR A QUESTION NO ONE ANSWERED Which country did Hitler invade that triggered the all-out conflict in Europe?PolandGreeceSpainGreat Britain Classify the object with the given side lengths as acute, obtuse, right, or not a triangle.16, 21, 28RightAcuteObtuseNot a triangle Can someone pleaseeee help and if youre correct ill cc give brainlies Help Asap Pls Hurry I Will Give Brainliest! Please select the word from the list that best fits the definitionThe stage in which you examine ideas, perhaps using a graphic organizer. Question ProgressHomework Progress4/Work out the size of angle x.105140