[tex]\tt{}( - 9p + 7) - (9p + 3)[/tex]
[tex]\tt{} - 9p - 7 + 9p + 3[/tex]
[tex]\tt{}7 - 3[/tex]
[tex]\tt{}4[/tex]
Assume that the helium porosity (in percentage) of coal samples taken from any particular seam is normally distributed with true standard deviation 0.78.
(a) Compute a 95% CI for the true average porosity of a certain seam if the average porosity for 15 specimens from the seam was 4.85. (Round your answers to two decimal places.)
(b) Compute a 98% CI for true average porosity of another seam based on 11 specimens with a sample average porosity of 4.56. (Round your answers to two decimal places.)
(c) How large a sample size is necessary if the width of the 95% interval is to be 0.46? (Round your answer up to the nearest whole number.)
(d) What sample size is necessary to estimate true average porosity to within 0.18 with 99% confidence? (Round your answer up to the nearest whole number.)
Answer:
a) The 95% CI for the true average porosity of a certain seam if the average porosity for 15 specimens from the seam was 4.85 is (4.46, 5.24).
b) The 98% CI for true average porosity of another seam based on 11 specimens with a sample average porosity of 4.56 is (4.01, 5.11).
c) A sample size of 12 is needed.
d) A sample size of 125 is needed.
Step-by-step explanation:
(a) Compute a 95% CI for the true average porosity of a certain seam if the average porosity for 15 specimens from the seam was 4.85.
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 = 1.96\frac{0.78}{\sqrt{15}} = 0.39[/tex]
The lower end of the interval is the sample mean subtracted by M. So it is 4.85 - 0.39 = 4.46
The upper end of the interval is the sample mean added to M. So it is 4.85 + 0.39 = 5.24
The 95% CI for the true average porosity of a certain seam if the average porosity for 15 specimens from the seam was 4.85 is (4.46, 5.24).
(b) Compute a 98% CI for true average porosity of another seam based on 11 specimens with a sample average porosity of 4.56. (Round your answers to two decimal places.)
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 - 0.98}{2} = 0.01[/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 - 0.01 = 0.99[/tex], so Z = 2.327.
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 = 2.327\frac{0.78}{\sqrt{11}} = 0.55[/tex]
The lower end of the interval is the sample mean subtracted by M. So it is 4.56 - 0.55 = 4.01
The upper end of the interval is the sample mean added to M. So it is 4.56 + 0.55 = 5.11
The 98% CI for true average porosity of another seam based on 11 specimens with a sample average porosity of 4.56 is (4.01, 5.11).
(c) How large a sample size is necessary if the width of the 95% interval is to be 0.46?
95% CI means that [tex]z = 1.96[/tex]
A sample of n is needed, and n is found when M = 0.46. So
[tex]M = z\frac{\sigma}{\sqrt{n}}[/tex]
[tex]0.46 = 1.96\frac{0.78}{\sqrt{n}}[/tex]
[tex]0.46\sqrt{n} = 1.96*0.78[/tex]
[tex](\sqrt{n})^2 = (\frac{1.96*0.78}{0.46})^2[/tex]
[tex]n = 11.05[/tex]
Rounding up
A sample size of 12 is needed.
(d) What sample size is necessary to estimate true average porosity to within 0.18 with 99% confidence?
99% CI means that [tex]z = 2.575[/tex]
A sample of n is needed, and n is found when M = 0.18. So
[tex]M = z\frac{\sigma}{\sqrt{n}}[/tex]
[tex]0.18 = 2.575\frac{0.78}{\sqrt{n}}[/tex]
[tex]0.18\sqrt{n} = 2.575*0.78[/tex]
[tex](\sqrt{n})^2 = (\frac{2.575*0.78}{0.18})^2[/tex]
[tex]n = 124.5[/tex]
Rounding up
A sample size of 125 is needed.
HELP ASAP!!!!! 20PTS!!
Answer:
the answer is 80!!!!!!!!!!
Step-by-step explanation:
Can you plz help I don’t understand
Answer: 4.2
Step-by-step explanation:
Simplify the following expression
6y + 8 - 2y + 5y - 9
Answer: 9y-1
:))))))))))))))))))))
Brainliest will be given ASAP question below!
Answer:
3/32
Step-by-step explanation:
9/16 × 3/4=27/144=3/16×1/2=3/32
Please solve this math question.
Answer:
none of these
Step-by-step explanation:
the side lengths are are 2√5/5, 2, and 4.
sin(x) = opp/hyp
sin(x) = 2/2√5
Complete the congruency statement for the triangles
Answer:
∆ABC ≅ ∆EDF by the SAS Congruence Theorem.
Step-by-step explanation:
<A ≅ <E,
Side length AC ≅ Side length EF
Side length AB ≅ Side length ED,
Thus, this implies that an included angle and two sides of one triangle are congruent to an included angle and 2 corresponding side lengths of the other triangle.
Therefore, we would conclude that:
∆ABC ≅ ∆EDF by the SAS Congruence Theorem.
How do you get infinitely many solution?
Answer: I’m
Step-by-step explanation: I’d not knkw
B:
The usual monthly expenses of midas family is 3500.00 for their electric and and with bill, 10,
000 for house and 5,000.00 for their food. The rest of their income will be their savings How much
will be their savings if the couple both earn 10,000.00each
Answer:
$1,500
Step-by-step explanation:
Income - Expenses = Savings
Income = 2 × 10,000 = $20,000
Expenses = 3,500 + 10,000 + 5,000 = $18,500
$20,000 - $18,500 = $1,500 left for Savings
NEED HELP I SUCK AT GEOMETRY (OFFERING 100POINTS)!!! best answer get brainlest
Find the measure of angle C
show work and explain!
Answer:
Angle C = 45°
Step-by-step explanation:
Hello There!
If you didn't know opposite angles are congruent in parallelograms
So ∠A≅∠C and ∠B≅∠D
So if ∠A = 45° then ∠C also equals 45°
As it is a parallelogram
[tex]\\ \sf\longmapsto <B\cong <D[/tex]
[tex]\\ \sf\longmapsto <A\cong <C[/tex]
<A=45°[/tex][tex]\\ \sf\longmapsto <C=<A=45°[/tex]
7.59 x 10^5 in standard form
[tex]\huge\text{Hey there!}[/tex]
[tex]\mathsf{7.59 \times 10^5}[/tex]
[tex]\mathsf{10^5}[/tex]
[tex]\mathsf{= 10(10)(10)(10)(10)}[/tex]
[tex]\mathsf{10(10) = 100}[/tex]
[tex]\mathsf{= 100(100)(10)}[/tex]
[tex]\mathsf{100(100) = 10,000}[/tex]
[tex]\mathsf{= 10,000(100)}[/tex]
[tex]\mathsf{= 100,000}[/tex]
[tex]\mathsf{7.59(100,000)}[/tex]
[tex]\mathsf{= \bf 759,000}[/tex]
[tex]\boxed{\boxed{\huge\text{Answer: \bf 759,000}}}\huge\checkmark[/tex]
[tex]\text{Good luck on your assignment and enjoy your day!}[/tex]
~[tex]\frak{Amphitrite1040:)}[/tex]
Which regular polygon would have each of its interior angles measure 140°?
octagon
nonagon
decagon
heptagon
9514 1404 393
Answer:
nonagon
Step-by-step explanation:
The adjacent exterior angle is 180° -140° = 40°. There are 360°/40° = 9 of those angles around the regular polygon, so it is 9-sided.
The polygon is a nonagon.
Answer:
nonagon
Step-by-step explanation:
i got 100%
Can someone please help me
Answer:
135ft^3
Step-by-step explanation:
Volume for triangular prism = 1/2bhl
v=1/2*6*5*9= 135
How many distinct variables does the expression below
contain?
2x^5+xy^4-zx
Cellulon, a manufacturer of home insulation, wants to develop guidelines for builders and consumers on how the thickness of the insulation in the attic of a home and the outdoor temperature affect natural gas consumption. In the laboratory, it varied the insulation thickness and temperature. A few of the findings are:
Monthly Natural Gas Consumption (cubic feet), Thickness of Insulation (inches), Outdoor Temperature (ºF),
y x1 x2
30.3 6.0 32.0
25.2 12 40
30.5 8 49
On the basis of the sample results, the regression equation is:
yˆ y^ = 57.25 − 1.07x1 − 0.64x2
According to the regression equation, the predicted Monthly Natural Gas Consumption (ŷ) can be estimated by subtracting 1.07 times the Thickness of Insulation (x1) and 0.64 times the Outdoor Temperature (x2) from 57.25.
The regression equation provided is:
ŷ = 57.25 - 1.07x1 - 0.64x2
Where:
ŷ represents the predicted value of Monthly Natural Gas Consumption (cubic feet)
x1 represents the Thickness of Insulation (inches)
x2 represents the Outdoor Temperature (ºF)
Based on the regression equation, the coefficients indicate the relationship between the independent variables (Thickness of Insulation and Outdoor Temperature) and the dependent variable (Monthly Natural Gas Consumption).
The coefficient for x1 (Thickness of Insulation) is -1.07. This means that, holding the Outdoor Temperature constant, for every 1-inch increase in the Thickness of Insulation, the predicted Monthly Natural Gas Consumption is expected to decrease by 1.07 cubic feet.
The coefficient for x2 (Outdoor Temperature) is -0.64. This means that, holding the Thickness of Insulation constant, for every 1-degree Fahrenheit increase in the Outdoor Temperature, the predicted Monthly Natural Gas Consumption is expected to decrease by 0.64 cubic feet.
The constant term in the equation is 57.25. This represents the predicted Monthly Natural Gas Consumption when both the Thickness of Insulation and Outdoor Temperature are zero.
for such more question on regression equation
https://brainly.com/question/22077082
#SPJ8
If 70% of a number is 126 and 95% of the same number is 171, find 25% of that number.
Answer:
45
Step-by-step explanation:
70%=126
100%=?
100×126=12600÷70
=180
100=180
25=?
25×180÷100
=45
3. Mateus recebe a visita do seu avô Pedro a cada 15 dias. João, o tio dele, o visita a cada 100
e, devido a escalas de trabalho, a cada 12 dias Mateus vai à praia com seus pais. Um belo dia Mans
recebeu a visita do seu avô, do seu tio e foi à praia com seus pais (com o avô e o tio que o visitavam nese
dia). Quantos dias depois este acontecimento se repetirà?
Answer:
Este acontecimento se repetirá 300 dias depois.
Step-by-step explanation:
Quando os eventos se repetirão no mesmo dia?
Cada evento tem uma frequência.
Eles ocorrem simultaneamente a cada x dias, e x é dado pelo MMC(Mínimo Múltiplico Comum) entre as frequência.
Neste problema:
A cada 15 dias o avô visita.
A cada 100 dias o tio visita.
A cada 12 dias vai à praia.
Quantos dias depois este acontecimento se repetirá?
Os três no mesmo dia vão se repetir após x dias, em que x é dado pelo MMC de 15, 100 e 12
MMC de 15, 100 e 12
Fatorando simultâneamente estes valores:
15 - 100 - 12|2
15 - 50 - 6|2
15 - 25 - 3|3
5 - 25 - 1|5
1 - 5 - 1|5
1 - 1 - 1
Então:
mmc(15,100,12) = 2*2*3*5*5 = 300
Este acontecimento se repetirá 300 dias depois.
I need help on this..... FAST. Think you can help me?
Answer:
.si sey el senocar 18
Step-by-step explanation:.basflone ne ombla
Will the product of 22.65 x 0.999 be greater than or less than 22.65? Without calculating, explain how you know.
It will be less since as common knowledge, it's a decimal so it'll be a little bit less
A carpenter buys a box containing 0.6 kilogram of nails. Each nail has a mass of 5 grams. How many nail are in the box?
Solve for w. Only use numbers in your answer.
8w - 15 = 57
w =
Answer:
w = 9
Step-by-step explanation:
1. Add 15 from both sides: 8w = 72
2. Divide my 8: w = 9
Answer:
the answer for this question is 9
Covert 2/3 years to months
Answer:
7.9 or if you need to round it,it will be 8
Step-by-step explanation:
dont have a explanation nut i hopes this help.
What is the slope of a line that is perpendicular to the line y = 1/6+ 4
+4?
Answer:
y = 6x + 8?
Step-by-step explanation:
The starting equation was unclear but if its perpindecular, flip the given slope. For example, if the slope was 3/4, its perpindecular slope would be 4/3.
A state university locks in costs for a student once a student starts attending the university. The total cost is $23,500. A student has
the following help in covering the costs of school.
• An academic scholarship of $8,200.
• Other scholarships and grants of $7.400.
Grandparents pay $1,000
.
What is the amount that the student will need to save every month in order to pay off the remaining costs in 10 months ?
$690
S820
S1 660
$2 350
Answer:
720
Step-by-step explanation:
24500 (total) subtracted by (10,700 + 5000 + 1600) =7200. 7200 divide by 10 mo=720
If the student will need to save every month in order to pay off the remaining costs in 10 months, the amount she will need to save per month is $690
Amount and interestGiven the following information from the question
The total cost of fee = $23,500
Amount got as help;
An academic scholarship of $8,200.
Other scholarships and grants of $7.400.
Grandparents pay $1,000
Amunt she had = 8200 + 7400 + 1000
Amount she had = $16600
Amount remaining = 23500 - 16600
Amount remaining = $6900
If the student will need to save every month in order to pay off the remaining costs in 10 months, the amount she will need to save per month is $690
Learn more on the amount here:
https://brainly.com/question/25109150
How many invitations should Tyler make each day if his goal is 122 and he already made 66 and he wants to finish in a week
Can you please help I am getting graded:) show work too please
Answer: A - 33/100
Step-by-step explanation:
You have to multiply the first fraction by 10 to make 100 the least common denominator - 3/10(10) = 30/100
Add 30/100+3/100 = 33/100
an employer pays three workers x,y,z a total amount of 6100 a month. x is paid 125% of the amount y is paid; which represent 80% of the amount z is paid. how much does x receive a month
Answer:
X earns $ 2,178.57, as does Z, while Y earns $ 1,742.85.
Step-by-step explanation:
Since an employer pays three workers X, Y and Z a total amount of $ 6100 a month, of which X is paid 125% of the amount Y is paid; which represents 80% of the amount Z is paid, to determine how much does X receive a month the following calculation must be performed:
X = 1.25Y
Y = 0.8Z
Z = Z
Z + Y + X = 6,100
Z + 0.8Z + (1.25 x 0.8Z) = 6,100
Z + 0.8Z + Z = 6,100
2.8Z = 6,100
Z = 6,100 / 2.8
Z = 2,178.57
Y = 0.8 x 2,178.57 = 1,742.85
X = 1,742.85 x 1.25 = 2,178.57
2,178.57 + 2,178.57 + 1,742.85 = X
6,099.99 = X
Thus, X earns $ 2,178.57, as does Z, while Y earns $ 1,742.85.
Helppppp meeeee!!!!!!!!!!!
Answer and Step-by-step explanation:
When it says (f + g)(x), it means that it wants you to add the functions together.
So, let's add them.
[tex](2x^2 + 6x - 4) + (5x^3 -6x^2-3)\\\\\\5x^3 - 4x^2 + 6x - 7\\\\\\\\\\\\\\5x^3 - 4x^2 + 6x - 7[/tex]is the answer. (Answer choice B.)
#teamtrees #PAW (Plant And Water)
0.8 as a fraction??
You can give your answer
Answer: 4/5
Step-by-step explanation:
0.8 = 8/10 = 4/5
Answer:
4/5
Step-by-step explanation:
What is the equation of the line that passes through the point (-6, -6) and has a
slope of - 1/3
Answer:
The equation of the line is [tex]y = -\frac{1}{3}x - 8[/tex]
Step-by-step explanation:
Equation of a line:
The equation of a line has the following format:
[tex]y = mx + b[/tex]
In which m is the slope and b is the y-intercept.
Slope of - 1/3
This means that [tex]m = -\frac{1}{3}[/tex]
So
[tex]y = -\frac{1}{3}x + b[/tex]
Through the point (-6, -6)
This means that when [tex]x = -6, y = -6[/tex]. So
[tex]y = -\frac{1}{3}x + b[/tex]
[tex]-6 = -\frac{1}{3}(-6) + b[/tex]
[tex]b + 2 = -6[/tex]
[tex]b = -8[/tex]
The equation of the line is [tex]y = -\frac{1}{3}x - 8[/tex]