The concentration of carbon monoxide (CO) in a gas sample is measured by a spectrophotometer and found to be 85 ppm. Through long experience with this instrument, it is believed that its measurements are unbiased and normally distributed, with an uncertainty (standard deviation) of 9 ppm. Find a 95% confidence interval for the concentration of CO in this sample. Round the answers to two decimal places. The 95% confidence interval is

Answers

Answer 1

Answer:

The confidence interval is [tex](85 - \frac{14.81}{\sqrt{n}},85 + \frac{14.81}{\sqrt{n}})[/tex], in which n is the size of the sample.

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 Z-table as such z has a p-value 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 = 1.645\frac{9}{\sqrt{n}} = \frac{14.81}{\sqrt{n}}[/tex]

The lower end of the interval is the sample mean subtracted by M. So it is [tex]85 - \frac{14.81}{\sqrt{n}}[/tex]

The upper end of the interval is the sample mean added to M. So it is [tex]85 + \frac{14.81}{\sqrt{n}}[/tex]

The confidence interval is [tex](85 - \frac{14.81}{\sqrt{n}},85 + \frac{14.81}{\sqrt{n}})[/tex], in which n is the size of the sample.


Related Questions

Is the following polynomial or not
5xy^2+3x^2y-2x^2y^2

Answers

9514 1404 393

Answer:

  is a polynomial

Step-by-step explanation:

The expression is a sum of products.

Each product involves a numerical value and a product of variables to positive integer powers.

These meet the requirements for an expression to be a polynomial, so ...

  the given expression is a polynomial

What's the measure of an arc with a central angle of 120°?

Answers

Answer:

the answer is 240 degrees

d) A movie time was 2hours. 10% of the time was taken advertisement. How long was the actual movie? ​

Answers

Answer:

108 minutes

Step-by-step explanation:

Lets say that M+A is the time of the movie and the advertisement, so;

M+A = 2

And we know that 10% of that time is advertisement, mathematically that is:

A = 0,1*2

So replacing the second equation in the first one we have;

M + 0,1*2 = 2

M = 2-0,1*2 = 1,8 hours

We can convert hours into minutes multiplying by 60

1,8h*60min/h = 108min

Please solve the equation 4X-25=71

Answers

x=24
im not sure if thats what you’re looking for but this is what i got :)
4x-25=71
4x=71+25
4x=96
x=96/4
x=24

Hope it is useful ;)

The graph shows the distribution of the number of text messages young adults send per day. The distribution is approximately Normal, with a mean of 128 messages and a standard deviation of 30 messages.

What percentage of young adults send more than 158 text messages per day?


16%

34%

68%

84%

Answers

Answer:

You'd think its 34% but apparently it's 16%.

I hope this is right. If its not then it must be 34%.

(A) -- or maybe (B). 80% confident it is A.

ED2021

Select the expression that represents the following statement: 3 times one fourth the difference of 26 and 10.

one fourth x (26 + 10) x 3
one fourth x (26 − 10) x 3
3 x one fourth x 26 − 10
3 x one fourth x 26 x 10
PLEASEE HEPPP

Answers

Answer:

the second option #2

one fourth x (26-10) x 3

Step-by-step explanation:

Two of the options (#1 and #4) can be ruled out immediately since they don't involve the difference of 26 and 10.

#3 can be ruled out because the difference needs to be multiplied by one fourth, but this option gives the wrong answer since the multiplication is done before subtraction (BODMAS)

Answer:

c

Step-by-step explanation:

I got it correct on a quiz

giả sử tỷ lẹ bệnh nhân tại 1 thành phố là a%
khám ngẫu nhiên b người tại thành phố này tính khả năng 2B + A người có bệnh

Answers

Answer:

ask in English then I can help u

Question 3 of 28
What is the length of IN in the right triangle below?
M
19
N
O A. 442
B. 442
O c. 1200
D. 280

Answers

Answer:

Option C. √280

Step-by-step explanation:

From the question given above, the following data were obtained

MN = 19

ML = 9

LN =?

We can obtain the value of LN by using the pythagoras theory as illustrated:

M ² = ML² + LN²

19² = 9² + LN²

361 = 81 + LN²

Collect like terms

361 – 81 = LN²

280 = LN²

Take the square root of both side

LN = √280

Therefore, the length of LN is √280

Find x so that the points (x,x+1), (x+2,x+3) and (x+3,2x+4) form a right-angled triangle.

Answers

Let a, b, and c be vectors each starting at the origin and terminating at the points (x, x + 1), (x + 2, x + 3), and (x + 3, 2x + 4), respectively.

Then the vectors a - b, a - c, and b - c are vectors that point in directions parallel to each of the legs formed by the triangle with these points as its vertices.

If this triangle is to contain a right angle, then exactly one of these pairs of vectors must be orthogonal. In other words, one of the following must be true:

(a - b) • (a - c) = 0

or

(a - b) • (b - c) = 0

or

(a - c) • (b - c) = 0

We have

a - b = (x, x + 1) - (x + 2, x + 3) = (-2, -2)

a - c = (x, x + 1) - (x + 3, 2x + 4) = (-3, -x - 3)

b - c = (x + 2, x + 3) - (x + 3, 2x + 4) = (-1, -x - 1)

Case 1: If (a - b) • (a - c) = 0, then

(-2, -2) • (-3, -x - 3) = (-2)×(-3) + (-2)×(-x - 3) = 2x + 12 = 0   ==>   x = -6

which would make a - c = (-3, 3) and b - c = (-1, 5), and their dot product is not zero. Then the triangles vertices are at the points (-6, -5), (-4, -3), and (-3, -8).

Case 2: If (a - b) • (b - c) = 0, then

(-2, -2) • (-1, -x - 1) = (-2)×(-1) + (-2)×(-x - 1) = 2x + 4 = 0   ==>   x = -2

which would make a - c = (-3, -1) and b = (-1, 1), and their dot product is also not zero. The vertices are the points (-2, -1), (0, 1), and (1, 0).

Case 3: If (a - c) • (b - c) = 0, then

(-3, -x - 3) • (-1, -x - 1) = (-3)×(-1) + (-x - 3)×(-x - 1) = x ² + 4x + 6 = 0

but the solutions to x here are non-real, so we throw out this case.

So there are two possible values of x that make a right triangle, x = -6 and x = -2.

In the diagram below, the circle has a radius of 25 inches. The area of the shaded sector is 125π in^2. Determine and state the measure of angle Q of the shaded sector. Show all your work that leads to the final answer. Please take a CLEAR picture of your work and upload here. Thank you.

Answers

Answer:

72 degrees

Step-by-step explanation:

Area of a sector=(pi*r^2)*(Theta/360)

125*pi=pi*(625)*(theta/360)

(125*360)/625=theta

Theta=72 degrees

The angle theta of the sector of the given circle is 72 degrees.

We have given that,

In the diagram below, the circle has a radius of 25 inches.

The area of the shaded sector is 125π in^2.

What is the formula area of the sector?

[tex]Area \ of \ a \ sector=(pi*r^2)*(\Theta/360)[/tex]

Therefore we get,

[tex]125*pi=pi*(625)*(\theta/360)[/tex]

[tex](125*360)/625=\theta[/tex]

[tex]\theta=72 degrees[/tex]

Therefore we get the angle of the sector of the given circle is 72 degrees.

To learn more about the area of sector visit:

https://brainly.com/question/22972014

#SPJ2

For the function f(x) = x^2 + 4x -5 solve the following f(x)=0

Answers

That's a question about quadratic function.

Any quadratic function can be represented by the following form:

[tex]\boxed{f(x)=ax^2+bx+c}[/tex]

Example:

[tex]f(x)= -3x^2-9x+57[/tex] is a function where [tex]a=-3[/tex], [tex]b=-9[/tex] and [tex]c=57[/tex].

Okay, in our problem, we need to find the value of x when [tex]f(x)=0[/tex]. That's mean that the result of our function is equal to zero. Therefore, we have the quadratic equation below:

[tex]x^2+4x-5=0[/tex]

To solve a quadratic equation, we use the Bhaskara's formula. Do you remember the value of a, b and c? They going to be important right now. This is the Bhaskara's formula:

[tex]\boxed{x=\frac{-b\pm \sqrt{b^2-4ac} }{2a} }[/tex]

So, let's see the values of a, b and c in our equation and apply them in the Bhaskara's formula:

In [tex]x^2+4x-5=0[/tex] equation, [tex]a=1[/tex], [tex]b=4[/tex] and [tex]c=-5[/tex]. Let's replace those values:

[tex]x=\frac{-b\pm \sqrt{b^2-4ac} }{2a}[/tex]

[tex]x=\frac{-4\pm \sqrt{4^2-4\times1\times(-5)} }{2\cdot1}[/tex]

[tex]x=\frac{-4\pm \sqrt{16-(-20)} }{2}[/tex]

[tex]x=\frac{-4\pm \sqrt{16 + 20)} }{2}[/tex]

[tex]x=\frac{-4\pm \sqrt{36} }{2}[/tex]

[tex]x=\frac{-4\pm 6 }{2}[/tex]

From now, we have two possibilities:

To add:

[tex]x_1 = \frac{-4+6}{2} \\x_1=\frac{2}{2} \\x_1=1[/tex]

To subtract:

[tex]x_2=\frac{-4-6}{2} \\x_2=\frac{-10}{2} \\x_2=-5[/tex]

Therefore, the result of our problem is: [tex]x_1 = 1[/tex] and [tex]x_2=-5[/tex].

I hope I've helped. ^^

Enjoy your studies.  \o/

For f(x)=1/x^2-3, substitute h for x in the function to solve for f(h).

Answers

The required function of h i.e f(h) is expressed as

[tex]f(h) = \dfrac{1}{h^2-3}[/tex]

Substitution of a function means replacing a variable with another variable without changing the structure of such function. According to the function given, we can see that we are simply meant to replace x with h as shown below:

Given the expression

[tex]f(x) = \frac{1}{x^2-3}[/tex]

To get f(h), we will substitute f in place of x that is x -> h as shown

[tex]f(h) = \frac{1}{h^2-3}[/tex]

Hence the required function of h i.e f(h) is expressed as

[tex]f(h) = \dfrac{1}{h^2-3}[/tex]

Learn more: https://brainly.com/question/4357143

What’s the distance between (4,-9) and (5,3)

Answers

Answer: Distance = √145

Concept:

Here, we need to know the concept of the distance formula.    

The distance formula is the formula, which is used to find the distance between any two points.

If you are still confused, please refer to the attachment below for a clear version of the formula.

Solve:

Given information

(x₁, y₁) = (4, -9)

(x₂, y₂) = (5, 3)

Given formula

[tex]Distance = \sqrt{(x_2-x_1)^2+(y_2-y_1)^2}[/tex]

Substitute values into the formula

[tex]Distance = \sqrt{(5-4)^2+(3+9)^2}[/tex]

Simplify values in the parentheses

[tex]Distance = \sqrt{(1)^2+(12)^2}[/tex]

Simplify exponents

[tex]Distance = \sqrt{1+144}[/tex]

Simplify by addition

[tex]Distance = \sqrt{145}[/tex]

Hope this helps!! :)

Please let me know if you have any questions

Answer:

[tex]\boxed {\boxed {\sf \sqrt {145} \ or \ 12.04}}[/tex]

Step-by-step explanation:

The distance between 2 points is calculated using the following formula.

[tex]d= \sqrt {(x_2-x_1)^2+(y_2-y_1)^2)[/tex]

In this formula, (x₁, y₁) and (x₂, y₂) are the coordinates of the two points.

We know the two points are (4, -9) and (5,3). If we match the values of the points and the coordinating variable, we see that:

x₁ = 4y₁= -9 x₂ = 5 y₂ = 3

Substitute the values into the formula.

[tex]d= \sqrt { ( 5 -4)^2 + ( 3 --9)^2[/tex]

Solve inside the parentheses.

(5-4)= 1 (3 --9) = (3+9) = 12

[tex]d= \sqrt {(1)^2 + (12)^2}[/tex]

Solve the exponents.

(1)² = 1 *1 = 1 (12)² = 12 * 12 = 144

[tex]d= \sqrt{ 1+144}[/tex]

Add.

[tex]d= \sqrt{145[/tex]

Take the square root.

[tex]d=12.04159458[/tex]

Let's round to the nearest hundredth. The 1 in the thousandth place tells us to leave the 4 in the hundredth place.

[tex]d \approx 12.04[/tex]

The distance between the 2 points is √145 or approximately 12.04.

Find the length of BC, last one

Answers

Since this is a right triangle, we can use one of the three main trigonometric functions: sine, cosine, or tangent.

Remember: SOH-CAH-TOA

Looking from the given angle, we know the opposite side and want to know the adjacent side. Therefore, we should use the tangent function.

tan(54) = 16/BC

BC = 16/tan(54)

BC = 11.62 units

Hope this helps!

The Answer to the Length of BC is 90

Find the missing side of the triangle

Answers

Answer:

x = 4[tex]\sqrt{2}[/tex]

Step-by-step explanation:

Pytago:

x[tex]x^{2} +7^{2} = 9^{2} \\\\x = \sqrt{9^{2} - 7^{2} } x = 4\sqrt{2}[/tex]

Answer:

Step-by-step explanation:

a^2 + b^2 = c^2

7^2 + b^2 = 9^2

49 + b^2 = 81

b^2 = 81 - 49

b^2 = 32

b^2 = 5.65 or sqrt rt of 32

Plz someone help me

Answers

Step-by-step explanation:

yo

so sorry I can't

really answer it

What are four ways an inequality can be written?

Answers

Answer:

There are four ways to represent an inequality: Equation notation, set notation, interval notation, and solution graph.

5x^2-4x=6

Solve for X.

Answers

Answer:

x= (2+ √ 34) /5 , (2- √ 34) /5

decimal form= 1.566

Step-by-step explanation:

The area of a circle is 144cm².Find the radius​

Answers

Answer:

It's a decimal, so it's around 6.771cm

Step-by-step explanation:

First, divide 144cm² by pi, or 3.14. Then find the square root of the answer, giving you the radius. The formula for the area of a circle is pi x radius squared, so to find out the radius you just use this formula in reverse.

If I messed up or didn't make my explanation clear, please comment.

Answer:

radius is [tex]\frac{12}{\sqrt{\pi } }[/tex] = 6.77 cm

Step-by-step explanation:

we know,

[tex]\pi[/tex] × r² = Area

⇒ [tex]\pi[/tex] × r² = 144

⇒ r² =[tex]\frac{144}{\pi}[/tex]

⇒ r= [tex]\frac{12}{\sqrt{\pi } }[/tex]

∴ r= [tex]\frac{12}{\sqrt{\pi } }[/tex]

pls mark this as the braniliest

find the slope of a line perpendicular to each given line number 11

Answers

Answer:

Slope = 5

Step-by-step explanation:

To find the slope of a line perpendicular to a given line, take the opposite reciprocal of the given line's slope.

Ex. -1/5 ⇒ 5

Opposite = opposite sign (- ⇒ +)

Reciprocal = numerator and denominator flipped (1/5 ⇒ 5/1 = 5)

complete explanation ​

Answers

Answer:

[tex]x ^{m - 3} \div x^{m - 4} \\ \frac{ {x}^{m - 3} }{ {x}^{m - 4} } \\ \frac{ {x}^{m - 3 - m + 4} }{x} \\ \frac{ {x}^{1} }{x} \\ x \: and \: x \: will \: cancel \: each \: other \: hence \: answer \: will \: be \: 1[/tex]

Trong một lớp học có $35$ sinh viên nói được tiếng Anh, $25$ sinh viên nói được tiếng Nhật trong đó có $10$ sinh viên nói được cả tiếng Anh và tiếng Nhật. Mỗi sinh viên trong lớp nói được ít nhất một trong hai: tiếng Anh hoặc tiếng Nhật. Hỏi sỹ số của lớp là bao nhiêu

Answers

Answer:

please write this question in English then I give answer

A clothing factory makes small, medium, and large sweaters. Last week, the factory made
1,612 sweaters. The factory made 3 times as many small sweaters as large sweaters. They
made 3 times as many medium sweaters as small sweaters.
How many small sweaters did the factory make last week?

Answers

This requires finding the number of small sweaters the company made last week

Number of small sweaters the company produced last week is 372

Total sweaters made = 1,612

Let

Small sweaters = 3x

Medium sweaters = x

Large sweaters = 3(3x) = 9x

Total = small + medium + large

1,612 = 3x + x + 9x

1612 = 13x

Divide by 13

x = 1612/13

Medium sweaters = x = 124

Small sweaters = 3x

= 3(124)

= 372

Read more:

https://brainly.com/question/24326559

U looking for BRAINLIEST? I'll give it to the first person to get it right
What is the shape of the distribution shown below?

A: The distribution is skewed to the left.
B: The distribution is approximately symmetrical.
C: The distribution is skewed to the right.

Answers

Answer:

A: The distribution is skewed to the left.

Step-by-step explanation:

Skewness:

If the distribution has a long left tail, it is skewed to the left.

If it has a long right tail, it is skewed to the right.

Otherwise, it is approximately symmetrical.

In this question:

Lots of values on the start(left), few on the end(right), so it is skewed to the left, and the correct answer is given by option a.

Urgent please I neeed some help !!!!!!!!!!!!!!!!!!!!!! URGENT 20 point bonus

Answers

Answer:

113.1

Step-by-step explanation:

use the formula to solve for volume

Determine what type of model best fits the given situation: A 4% raise in salary each year.

Answers

the models aren't given..

Answer: no models given

Step-by-step explanation:

Write the greatest and smallest number of 8 suing following digits. 1,2,3,4,5,6,7,8

Answers

Answer:

Not very sure what you mean,

But in the provided set, 8 is the greatest number, and 1 is the smallest.

Hope this helps!!

6x47
Which multiple of 10 is closest to 47?

Answers

Answer:

50 is your answer:)

Step-by-step explanation:

Answer:

50

Step-by-step explanation:

50 is the multiple of 10 that is closest to 47.

In the accompanying diagram, ΔA′B′C′ is the image of ΔABC. Which type of transformation is shown in the illustration?

A. rotation
B. translation
C. reflection
D. dilation

Answers

Answer:

Reflection

Step-by-step explanation:

It is the opposite of the first,...

Economists predict that Americans will spend $1,180 on electonics in
2020. this is a 6.8% increase from last year. What did Americans spend
last year?

Answers

Money spent by Americans last year=$1,180-6.8% of $1,180
=$1099.76
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