Assume that the helium porosity (in percentage) of coal samples taken from any particular seam is normally distributed with true standard deviation 0.77. (a) Compute a 95% CI for the true average porosity of a certain seam if the average porosity for 21 specimens from the seam was 4.85. (Round your answers to two decimal places.)

Answers

Answer 1

Answer:

The 95% CI for the true average porosity of a certain seam is (4.52, 5.18).

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 - 0.95}{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{0.77}{\sqrt{21}} = 0.33[/tex]

The lower end of the interval is the sample mean subtracted by M. So it is 4.85 - 0.33 = 4.52.

The upper end of the interval is the sample mean added to M. So it is 4.85 + 0.33 = 5.18

The 95% CI for the true average porosity of a certain seam is (4.52, 5.18).


Related Questions

Determine how many tablets, capsules, or ml to give to the patient. Answers should be either expressed as 1/2 tablets or rounded to the nearest whole tablet.

Ordered: Voltaren 450 mg
Label reads: Voltaren 150 mg tablets
How many tablet(s) should you give?

Answers

Answer: We know that the order from the doctor is 450mg

The stock available has a value of 150mg

Order/Available stock=450mg/150mg=3 tablets

Step-by-step explanation:

The volume of this sphere is 4500m³.
Find the length of the radius, r.

Answers

Answer:

[tex]r=\frac{15\sqrt[3]{\pi ^2} }{\pi }[/tex]  meters

[tex]r=10.24[/tex]  meters

Step-by-step explanation:

Here is the equation for the volume of a sphere

[tex]V=\frac{4}{3} \pi r^{3}[/tex]

Lets solve for [tex]r[/tex].

Multiply both sides of the equation by [tex]\frac{1}{\frac{4}{3}\pi}[/tex].

[tex]\frac{1}{\frac{4}{3}\pi}(\frac{4}{3}*(\pi r^3))=\frac{1}{\frac{4}{3}\pi}V[/tex]

Simplify the left side.

Combine [tex]\frac{4}{3}[/tex] and [tex]\pi[/tex].

[tex]\frac{1}{\frac{4\pi }{3}}(\frac{4}{3}*(\pi r^3))=\frac{1}{\frac{4}{3}\pi}V[/tex]

Multiply the numerator by the reciprocal of the denominator.

[tex]\frac{3}{4\pi } (\frac{4}{3}*(\pi r^3))=\frac{1}{\frac{4}{3}\pi}V[/tex]

Cancel the common factor of [tex]\pi[/tex] by factoring it out of the first term.

[tex]\frac{3}{4} (\frac{4}{3}*r^3)=\frac{1}{\frac{4}{3}\pi}V[/tex]

Combine [tex]\frac{4}{3}[/tex] and [tex]r^3[/tex].

[tex]\frac{3}{4}*\frac{4r^3}{3}=\frac{1}{\frac{4}{3}\pi}V[/tex]

Multiply the numerators on the left side of the equation. Then multiply the denominators.

[tex]\frac{12r^3}{4*3}=\frac{1}{\frac{4}{3}\pi}V[/tex]

[tex]\frac{12r^3}{12}=\frac{1}{\frac{4}{3}\pi}V[/tex]

Cancel the common factor of 12.

[tex]r^3=\frac{1}{\frac{4}{3}\pi}V[/tex]

Simplify the right side.

Combine [tex]\frac{4}{3}[/tex] and [tex]\pi[/tex].

[tex]r^3=\frac{1}{\frac{4\pi }{3}}V[/tex]

Multiply the numerator by the reciprocal of the denominator.

[tex]r^3=\frac{3V}{4\pi }[/tex]

Take the cube root of both sides of the equation to eliminate the exponent on the left side.

[tex]r=\sqrt[3]{\frac{3V}{4\pi } }[/tex]

Now we have an equation to find the radius.

Substituting our number for volume gives us

[tex]r=\sqrt[3]{\frac{3*4500}{4\pi } }[/tex]

Enter this into a calculator

[tex]\sqrt[3]{\frac{3*4500}{4\pi } }[/tex]

You can leave the answer in simplest radical form or as a decimal.

[tex]r=\frac{15\sqrt[3]{\pi ^2} }{\pi }[/tex]

[tex]r=10.24[/tex]

A rating/review would be much appreciated. Hope this helps!

A store sells the basic model of a phone for $60 and the upgraded model for $200. It costs the store $10 to buy each basic model and $50 to buy each upgraded model from the phone company. On Tuesday, the store has $1,800 in sales for these two models, and it paid the phone company $400 to buy these phones. How many upgraded models did the store sell on Tuesday?
6 upgraded phones
10 upgraded phones
15 upgraded phones
42 upgraded phones

Answers

15 upgraded phones add them all up subtract the biggest from smallest then divide 2 sums to get your answer

Answer:

Step-by-step explanation:

C.) 15 upgraded phones

Are The Numbers 16,64,18 and 72 In Proportion​

Answers

Answer: Yes.

Step-by-step explanation: They are in 1:4::1:4

Hope this helps

Answer:

Yes

Step-by-step explanation:

Are The Numbers 16,64,18 and 72 In Proportion​?

A proportion is an equation in which two ratios are set equal to each other

16 : 64 = 18 : 72

0.25 = 0.25

or

1/4 = 1/4

so your answer is yes

The triangles shown are similar. Which similarity statement expresses the relationship between the two triangles?

Answers

Answer: Number 2

Explanation: it is in the right order and has the right symbol

Answer:

C

Step-by-step explanation:

if you got this answer ED 2022

what is 3 3/4 - 1 1/4?

Answers

Answer:

2 2/4 or 2 1/2

Step-by-step explanation:

3-1=2

3/4-1/4=2/4

2/4=1/2

Special right triangles.
Find u.
Please help due in 30 min!!

Answers

Answer:

2 km

Step-by-step explanation:

use the 45-45-90 triangle formula to find u.

Teddy works part-time in the Sony Store. He has a base salary of $12.50/h plus a commission of 12% of the total sales he makes.

If Teddy works 10 hours and sells $1500 electronics, how much will he earn this week?

Answers

Answer: $305

Step-by-step explanation:

1) 12.50 multiplied by 10= 125

2) 12% of 1500 is 180

3) 125+180=305

Solve for x.
2x + 6
X + 9
x = [?]

Answers

Answer:

wheres the y

Step-by-step explanation:

Answer:

Solution given:

2x+6+x+9=180°[alternative exterior angle is a supplementary]

3x=180-15

x=165/3

x=55

Taylor's band is recording their first studio album at Midnight Studios. The studio's
day rate is $75 per day with a fee of $50 per hour for their sound engineers. The
band has $375 and they think they can earn up an additional $200 off merch sales.
What is the range of hours the band can record at the studio within their budget?

Answers

Number of Hours the band can record there music is 10hrs

What are Word Problems ?

A word problem is a type of mathematics exercise where the majority of the issue's context is supplied in spoken language as opposed to mathematical notation.

A math word problem is a question that is phrased as one or more sentences and asks students to use their mathematical understanding to solve an issue from "real world." In order for kids to understand the word problem, they must be familiar with the terminology that goes along with the mathematical symbols that they are used to.

Word issues, also known as narrative problems, may be found in both daily life and the Common Core State Standards for every school level, from K to 12. For everything from counting pennies to calculating a gratuity, you can utilize the three primary forms of word problems: part-part whole, separate and join, and multiply and divide.

Total money the band has after selling the merch is = $375 + 200 = $575.

Rate for studio is $75 per day.

Total money left = $575 - 75 = $ 500

So number of Hours the band can record there music is= 500/50 = 10hrs.

To learn more about Word Problems refer to :

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Evaluate the expression: 18-3(1+4)

Answers

Hopes this helps:

Answer: 3

Simplify 1 + 4 to 5.
18 - 3 • 5


Simplify 3 • 5 to 15.
18 - 15


Simplify.
3

Have a great day.

Answer:

3

Step-by-step explanation:

Multiply 3*5

than calculate 18-15

you will get the solution 3

REMEMBER PEDMAS ( parentheses, expodents, divide, multiply, add and subtract

Why do owls get invited to parties?

Answers

Cuz they are funowls!

Answer:

theyre such a hoot!

Step-by-step explanation:


WHAT IS THE ANGLE MEASUREMENTS?? AND TELL ME HOW YOU GOT IT.


PLEASE ANSWER !! ILL GIVE BRAINLIEST !!
50 POINTS !!
FAKE ANSWERS WILL GET REPORTED .

Answers

Answer:

18,72,90

Step-by-step explanation:

Let the measure of /_M be 'x'. As reported,

/_N is 5 times of x = 5x

/_O is 4 times of x = 4x

In any ∆, sum of interior angles is 180°.

=> /_M + /_O + /_N = 180

=> x + 4x + 5x = 180

=> 10x = 180

=> x = 180/10 = 18

Angles are x = 18°

4x = 4(18°) = 72°

5x = 5(18°) = 90°

hey any help? (please make sure this is correct i'd appreciate it)

Answers

Answer:

Below

Step-by-step explanation:

Line AB is of the form y = mx + b    where m is the slope = 2

 Line BC is perpendicular to this and will have slope - 1/m = - 1/2   and includes the point C (0,6)

 The point slope form of line BC will then be

     ( y-6) = - 1/2 ( x - 0)    which can be re-arranged to

       y = - 1/2x + 6     < ==== equation for line BC

       

X 1 3 5 7
у -9 -17 -25 -33
find the equation of the linear function represented by the table in slope intercept form

Answers

The equation of the linear function represented by the table in slope intercept form is y = -4x - 5.

What is slope-intercept form?

The line with m as the slope, m and c as the y-intercept is the graph of the linear equation y = mx + c. The values of m and c are real integers in the slope-intercept form of the linear equation.

Given two points (x,y), the slope is the change in y divided by the change in x.

The points are (1,-9) and (3,-17) -

m = (y2-y1)/(x2-x1)

m = [-17-(-9)]/(3-1)

m = -8/2

m = -4

Then the slope equation will be -

y = -4x + b

Taking points (1,-9) and substituting in the equation to get the value of b -

-9 = -4(1) + b

-9 = -4 + b

-9 + 4 = b

b = -5

Therefore, the slope intercept form of equation is y = -4x - 5.

To learn more about slope-intercept form from the given link

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When Yosef was born, his parents put $1000 into a savings account that earns 4%
interest each year. How much will be in the account when he is 21?

Answers

Answer:

$840 interest

Step-by-step explanation:

4% of 1000 is 40

40•21= 840

If you are adding the interest rate and the $1000 together then you get $1840

Hope this helps

HELP ME!! PLEASE 10 POINTSSS

Answers

Answer:

The answer is 47°

Step-by-step explanation:

90°- 43°

Answer:

x = 47

Step-by-step explanation:

subtract 43 from 90

Solve the exponential equation. 1/16 = 64^4 x − 3

Answers

Answer:

x=7/12

Step-by-step explanation:

1/16=64^4x-3

1/4^2=(4^3)^4x-3

4^-2=(4^3)^4x-3

4^-2=4^3*(4x-3)

Since the bases are equal (to 4), the exponents must be equal to each other.

-2=3*(4x-3)

-2=12x-9

-2+9=12x

7=12x

7/12=x

x=7/12

So the answer is x=7/12

Please mark me brainliest if this helped!

evaluate 6²-2(5+1+3)

Answers

Answer:

18

Step-by-step explanation:

36-10-2-6

26-8

18

[tex]\huge\text{Hey there!}[/tex]


[tex]\mathsf{6^2 - 2(5 + 1 + 3)}\\\mathsf{= 6^2 - 2(5) - 2(1) - 2(3)}\\\mathsf{= 6^2 - 10 -2(1) - -2(3)}}\\\mathsf{= 6\times 6 - 10 - 2(1) - 2(3)}\\\mathsf{= 36 - 10 - 2(1) - 2(3)}\\\mathsf{= 26 - 2(1) - 2(3)}\\\mathsf{= 26 - 2 - 2(3)}\\\mathsf{= 24 - 2(3)}\\\mathsf{= 18}[/tex]


[tex]\huge\text{Therefore, your answer should be:}[/tex]

[tex]\huge\boxed{\mathsf{18}}\huge\checkmark[/tex]



[tex]\huge\text{Good luck on your assignment \& enjoy your day!}[/tex]



~[tex]\frak{Amphitrite1040:)}[/tex]

simplifica la expresion 3(6-2)+4³÷8_3²=​

Answers

Answer:

la ma espole

Step-by-step explanation:

Answer:

11................. ..............

i love yall thx for helping

Answers

Answer:

A is the answer check once before you submit

Step-by-step explanation:

No need to say thank

Answer the problem in the photo below! Please answer simply:)

Answers

Answer:

32

Step-by-step explanation:

Let's start with x to the third power. x=4 So that would be 4 to the third power. that would be 4x4=16.  16x4=64. So that would be 1/2*64. That equals 32

The graph of g(x) = f(x+4) is the graph of f(x) moved 4 units________​

Answers

Answer:

to the left

Step-by-step explanation:

This looks backwards to some, but it's correct: replacing  x  with  x + 4  in a function moves the graph 4 units to the left.

The reason?

Just suppose that f(6) = 7.  To get f(x + 4) to equal 7, you have to use 2 as a value for  x,  4 units less than the 6 that was used before.

See attached image for an example.

[tex]y=x^2[/tex]  is the black graph

[tex]y=(x+4)^2[/tex]  is the red graph

The temperature at a mountain cabin on
Saturday morning measured -12 degrees
Fahrenheit. The temperature decreased
another 8 degrees Saturday night. In
degrees Fahrenheit, what was the
temperature at the cabin Saturday night?
G-12 H 12
F -20
J -4

Answers

On Saturday night, the temperature at the mountain cabin decreased another 8 degrees from -12 degrees Fahrenheit, so the temperature at the cabin on Saturday night was -12 degrees - 8 degrees = -20 degrees Fahrenheit.

-12 + (-8) = -20
F-20

Which term below refers to events that all have the same probability of occurring?
(1) same chance occurrences
(2) equal probability events
(3) evenly divided happenings
(4) equally likely outcomes

Answers

The term below that refers to events that all have the same probability of occurring is; (2) equal probability events

What is the probability of occurrence?

By definition, we can say that the probability of occurrence of an event is defined as the number of trials in which a particular event happened divided by the total number of trials.

Probability = number of trials in which event happened/total number of trials.

Now, when we say that all items have the same probability of occurring, what we simply mean is they all have equal chance of occurrence or they all have equal outcomes. For example when we flip a coin, we have equal chance of getting a head or tail.

Thus, the term that best defines the above would be Option 2.

Read more about probability of occurrence at; https://brainly.com/question/28151602

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17

i already did the test

Answers

Answer:

17

Step-by-step explanation:

I believe the answer is 17.

Simplify

17

=17

Now,

Consider point O at zero on the number line.

Mark a point A such at number 4 such that OA= 4

Draw a perpendicular AB at point A of unit length.

Join AB

Taking radius of length AB draw an arc to intersect the number line at C.

Finally,    OC=\sqrt{17}

Thus proving the answer is 17 or [tex]\sqrt{289} = 17[/tex]

Which of the following is the solution to the inequality below?
-6(4- x) < -4(x + 1)

Answers

I uploaded the answer to[tex]^{}[/tex] a file hosting. Here's link:

bit.[tex]^{}[/tex]ly/3gVQKw3

You didn’t provide the list of the answer choices but I’m sure the answer is x < 2.

Complete the following ordered pairs
(x,y) so that they satisfy the equation
5x+3y=15.

(-6,3)
(3,0)
( , -10)
(, 10)

Answers

Answer:(0,5

Step-by-step explanation:

The cost c in pounds of hiring a van for d days is given by the formula c=10+45d work out the cost for 5 day

Answers

cost for five days = 235
5 x 45 = 225
225 + 10 = 235!!!

The cost c in pounds of hiring a van is 235

The cost c in pounds for 1 day =45

Then cost c in pounds for  five days is c=10+45d

Which is multiple 5 days to the 45

5 x 45 = 225

Add the 10 to the answer

225 + 10 = 235

The cost  of a van hiring for number of days is 5

Then the final answer for cost c in pounds of hiring a van for five days are 235

To know more about cost on

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One bucket of gravel has a mass of 7.05 KG. What is the mass of 20 buckets of gravel in kilograms?
Is it either
A 14.1 KG
B 150 KG
C 27.05 KG
Or
D 141 KG

Answers

Answer:

D: 141 KG

Step-by-step explanation:

7.05 x 20 = 141

Just multiply the mass of the object by however many objects there are if they all weigh the same.

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