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).
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.
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.
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.
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
A pack of 4 chocolate bars costs £1.20
What is the price per unit?
what is it?
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 £ 0.3x plus 1 > 3
The souliton is
Answer:
x > 2
Step-by-step explanation:
x + 1 > 3
Subtract 1 from both sides
x + 1 - 1 > 3 - 1
x > 2
hello if anyone would pls help
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.
4 quarts= how many gallons
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
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 :
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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
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
Plsss help will give brainlest no links or files plss
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
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
Answer:
A. (-1, 0)
Step-by-step explanation:
I calculated it logically
HELP PLEASE!!
Explain the error in the following exercise;
then correct it.
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
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?
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.
The difference of x and y is the same as 3 times the sum of x and 2
Answer:
x - y = 3(x + 2)
x - y = 3x + 6 is the simplified answer and is also correctStep-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.
An office building is 18 meters high. What
calculation would convert its height to
yards? Use 1 meters = 1.09 yards.
Answer:
19.62 yards
Step-by-step explanation:
18 x 1.09 = 19.62
The measure of an angle is 89. Find the measure of its supplement
a. 91
b. 89
c. 90
d. 80
Answer:
A. 91
Step-by-step explanation:
Supplementary angles are 2 angles that when added together, equal 180 degrees. 91+89=180
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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.
Answer:
I wish I can read all the text
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?
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
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
Answer:
C. 3 1/2Step-by-step explanation:
Estimate the fraction part of the number.
11/40 > 10/40 = 1/4We 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.
Is 3.37 less than 3.368
Answer:
no
Step-by-step explanation:
Answer:
it's not
Step-by-step explanation:
Can someone help me really please
Answer:
Step-by-step explanation:
question
Answer:
the tank at the pet store
Step-by-step explanation:
5x4x2 = 40
35<40
Solve the following system of equations:
x+2y=-4
x-2y=8
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
100 points
(algebra one)
describe and correct the error in comparing the graphs
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!! ❤
Plz help me well mark brainliest if correct................?
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
please find the value of X for number 4 5 and 6 thank you :)
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 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
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
Describe how to graph the solution of y ≤ −x2 + 2x.
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.
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
?
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
How many cubes with side lengths of 1/4 cm does it take to fill the prism?
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
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?
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%.