Exercise 4.28: Keeping water supplies clean requires regular measurement of levels of pollutants. The measurements are indirect—a typical analysis involves forming a dye by a chemical reaction with the dissolved pollutant, then passing light through the solution and measuring its “absorbance.” To calibrate such measurements, the laboratory measures known standard solutions and uses regression to relate absorbance and pollutant concentration. This is usually done every day. Here is one series of data on the absorbance for different levels of nitrates. Nitrates are measured in milligrams per liter of water. Data can be found on Crunchit>File>Load from> Chapter 4> Exercise 28. b) It is appropriate to find the correlation (r) because the form of the relationship is c) Chemical theory says that these data should lie on a straight line. If the correlation is not at least 0.997, something went wrong, and the calibration procedure is repeated. Find the correlation using Crunchit!. Correlation r = (Enter it exactly as it appears on Crunchit!) d) The calibration process sets nitrate level and measures absorbance. At this point it appears as if Nitrate level is x and the absorbance is y but the roles of x and y get switched. Once established, the linear relationship will be used to estimate the nitrate level in water from a measurement of absorbance. If we are going to estimate the Nitrate level then that becomes the response variable. What is the equation of the line used for estimation? Write it in the form ____ = _____ + ______*_____. The two variables are "Nitrates", "Absorbance". e) What is the estimated nitrate level in a water specimen with absorbance 40? Your answer must have two decimal places. mg/liter f) Based on the correlation r we can say that the predicted value (estimate) of nitrate level is (very good/good/bad) g) The percent of the variation in Nitrate s that can be explained by absorbance is %. (two decimal places) h) We will only be able to use the regression equation to make predictions of nitrates for absorbance between nd . That is, we cannot plug in a number outside this range into the the regression equation to make a prediction

Answers

Answer 1

Answer:

..

Step-by-step explanation:


Related Questions

The quotient of a number and
four is two

Answers

Answer:

x/4=2

Since it's not said, the number represent a variable which we'll write as "x". The word "is" means "equals".

Stephanie has 3.5 bags of soil to put in her garden. Each bag of aoil will cover 125.3 ft2. How many square feet will stephanie be able to cover if she uses all these bags of soil?

Answers

Answer:

438.55 ft²

Step-by-step explanation:

1 bag = 125.3 ft²

3.5 bags = 125.3 • 3.5 ft²

= 438.55 ft²

Answer:

Step-by-step explanation:

125.3*3.5

438.55

If f(x) = 3x — 2 and g(x) = х + 5, thеn f(g(x)) =

Answers

I think is A sorry if is wronge

Answer:

D) 3x+13

Step-by-step explanation:

f(x+5)

-2+3(x+5)

-2+3x+15

3x+15-2

3x+13

given f(x)=9+2x find f(3)

Answers

Answer:

15.

Step-by-step explanation:

f(x)=9+2x

x = 3, so f(3) = 9 + 2(3)

= 15.

3x-24=5x what’s the answer

Answers

Answer:

x = -12

Step-by-step explanation:

3x-24=5x

3x-5x=24 (move x's to same side by adding 24, and subtract 5x)

-2x = 24 (combine like variables, 3x-5x)

x = -12 (divide by -2)

Please help me thank you

Answers

Answer:

(-3,2)

Step-by-step explanation:

Brackets cannot be mixed with other types of punctuation like these { }, [ ]. Once you use a bracket, you have to close the sentence or equation with a closed bracket. Ex: (Like this) Maths equation: 3 x (4/5) + 19=

Evaluate if x = 2 and y = -4: x³ + y² *

Answers

Answer:

=24

Step-by-step explanation:

Evaluate for x=2,y=−4

23+(−4)2

23+(−4)2

Multiply, Express your answer in simplest form. 5/8 x 24​

Answers

Answer: 15

120/8 = 60/4 = 15

Answer:

15

Step-by-step explanation:

What are some combinations you can buy for lunch?

How much are you spending on your choice

Answers

Answer:

You can spend all of the money by getting 1 sandwich and 2 things of chips

Step-by-step explanation:

1 sandwich =4$

1 bag of chips =3$

4 + 3 =7

7+ 3= 10

Gold mines in northern Nevada produce an average of 3.2 grams of gold per short ton (2,000 pounds) of ore. The value of gold is usually reported in troy ounces (ozt), and a troy ounce is equal to 31.1 grams (g). On average, how many troy ounces of gold are extracted from one short ton of Nevada ore

Answers

Answer:

0.1028938

Step-by-step explanation:

Given the following :

Average gold production in Northern Nevada =3.2 grams per short ton (2000 pounds)

Value of gold is measured in Troy ounces (ozt)

1 Troy ounces = 31.1 grams(g)

Number of Troy ounces of gold extracted from one short ton of Nevada ore ; let the number be t:

1 ozt = 31.1 g

t = 3.2 g

Cross multiply :

31.1 × t = 3.2 × 1

31.1t = 3.2

t = 3.2 / 31.1

t = 0.1028938 ozt

Hence, On average, 0.1028938 ozt of gold is extracted from one short ton of Nevada ore

HELP ITS DUE IN A FEW MINUTES!!!!!! I’ll brainlist!!!

Answers

Answer:

8

Step-by-step explanation:

68/8.2=8

Find the cardinal number of the set
C = {x|x € N, 30 < x < 56 and x is divisible by 6},

Answers

Answer: 4

=====================================================

Explanation:

We're given the following

[tex]C = \{ x | x \in \mathbb{N}, \ 30 < x < 56, \ \text{ x is divisible by 6}\}[/tex]

which means that we have a set of natural numbers between 30 and 56, excluding both endpoints, and the set of numbers are also multiples of 6.

So looking at the multiples of 6 that are between 30 and 56 leads us to

{30, 36, 42, 48, 54}

but we cross off 30 as we want x to be larger than that, so we get this updated final list

{36, 42, 48, 54}

There are four items in this final list so the cardinality of the set described is 4. The cardinality is just the number of items in a given set.

Divide $9000 in the Ratio 3:1:6.

Answers

Answer:

The ratio of monthly income to the savings in a family is 5 : 4 If the savings be $9000, find the income and the expenses.

2. What should be added to the ratio 5 : 11, so that the ratio becomes 3 : 4?

3. Two numbers are in the ratio 7 : 5. If 2 is subtracted from each of them, the ratio becomes 3 : 2. Find the numbers.

4. Two numbers are in the ratio 3 : 7. If their sum is 710, find the numbers.

BRAINLIEST TO THE FIRST PERSON TO ANSWER!!Maria solved an equation as shown below.

3 (x + 6) = 5 (x minus 4). 3 x + 18 = 5 x minus 20. 38 = 2 x. 19 = x.

What is the solution to Maria’s equation?
19
38
no solution
infinitely many solutions

Answers

Answer:

19

Step-by-step explanation:

3(x + 6) = 5(x - 4)

Distribute on both sides.

3x + 18 = 5x - 20

Subtract 3x from both sides. Add 20 to both sides.

38 = 2x

Divide both sides by 2.

19 = x

Maria followed the steps shown above and solved the equation correctly.

The solution is x = 19.

Answer: x = 19

Answer:

A. 19

Have a great day :D

5. Box A contains one white ball and two red balls. Box B contains one white ball and three red balls. A ball is picked at random from box A and put into box B and mixed around. A ball is then picked at random from box B. What is the probability that this final pick is white

Answers

Answer: 7/12

Step-by-step explanation:

given data:

Box A

white ball = 1

red ball = 2

total ball = 3.

Box B

white ball = 1

red ball = 3

total ball = 4

Probability of picking a white ball as the final pick.

= 1/3 + 1/4

get the LCM = 12

= 4*1 + 1*3 /12

= 4 + 3 /12

= 7/12

T(d) is a function that relates the number of tickets sold for a movie to the number of days since the movie was released.
The average rate of change in TQ) for the interval d = 4 and d = 10 is 0. Which statement must be true?
O The same number of tickets was sold on the fourth day and tenth day.
O No tickets were sold on the fourth day and tenth day.
O Fewer tickets were sold on the fourth day than on the tenth day.
More tickets were sold on the fourth day than on the tenth day.

Answers

Answer: The same number of tickets was sold on the fourth day and tenth day.

Step-by-step explanation:

Given: [tex]T(d)[/tex] is a function that relates the number of tickets sold for a movie to the number of days 'd' since the movie was released.

Also, the  average rate of change in T(d) for the interval d = 4 and d = 10 is 0.

Since the average rate determines the rate of change in the dependent variable (T(d)) with respect to the independent variable (d).

It means that there is no change from 4th day to 10th day in the number tickets sold.

Hence, the correct option is "The same number of tickets was sold on the fourth day and tenth day."

Answer:

A

Step-by-step explanation:

use grids to find the factor pairs for 48

Answers

Answer:

1 x 48, 2 x 24, 3 x 16, 4 x 12, or 6 x 8. Factors of 48: 1, 2, 3, 4, 6, 8, 12, 16, 24,

Step-by-step explanation:

u need to find the highest common factor

Molly has $45 in her wallet, which is 3 times as much money as her brother has.

Answers

Answer:

Her brother has $15

Step-by-step explanation:

How come Molly has $45 which is as 3 times as much money as her brother has, we divide 45 by 3 which gives us $15.

(I don't really know what your question is but I hope this helped.)

Write 4,000+600+7in standard form

Answers

Answer: 4,607 would be the correct answer. Hope your having a great day!!!

What is 90.125 written in expanded form? A. 9 × 10 + 1 × 1 + 2 × 1 10 + 5 × 1 100 B. 9 × 1 + 1 × 1 10 + 2 × 1 100 + 5 × 1 1 , 000 C. 9 × 10 + 1 × 1 10 + 2 × 1 100 + 5 × 1 1 , 000 D. 9 × 1 + 1 × 1 100 + 2 × 1 1 , 000 + 5 × 1 10 , 000

Answers

Using digit concepts, it is found that, in expanded form:

[tex]90.125 = 9 \times 10^1 + 0 \times 10^0 + 1 \times 10^{-1} + 2 \times 10^{-2} + 5 \times 10^{-3}[/tex]

--------------------

Each number can be divided into an integer part and a decimal part. For 90.125, the integer part is 90 and the decimal part is 0.125.In the integer part, starting from the last digit, each is multiplied by the "next" power of 10, thus:

[tex]90 = 0 \times 10^{0} + 9 \times 10^{1} = 9 \times 10^{1} + 0 \times 10^{0}[/tex]

For the decimal part, starting from the first decimal digit, the same logic applies, using negative powers of 10 starting at -1, thus:

[tex].125 = 1 \times 10^{-1} + 2 \times 10^{-2} + 5 \times 10^{-3}[/tex]

Combining the integer and decimal parts, we get that the number in expanded form is:

[tex]90.125 = 9 \times 10^1 + 0 \times 10^0 + 1 \times 10^{-1} + 2 \times 10^{-2} + 5 \times 10^{-3}[/tex]

A similar problem is given at https://brainly.com/question/17574571

Answer:

B is right

Step-by-step explanation:

Which represents the solution set of the inequality 6x-9​

Answers

Answer:

3(2x-3)

Step-by-step explanation:

6x-9 Common factor is 3

6x/3 = 2x

-9/3 = -3

3(2x - 3)

plz answer this i will marku pleeeeeeeeeezz​

Answers

Answer:

x= 105 also because it's a z angle

y= 180-105

=75

x=z which is 105, because they are alternative angles.

The given angle of 105 and angle z are consecutive interior angles and need to equal 180 degrees.

Z = 180-105 = 75 degrees

Angle z and angle c are vertical angles and are identical so angle x also equals 75 degrees

Angle y and 105 are supplementary angles and when added equal 180

Angle y is 180-105 = 75

X, y and z are all 75 degrees

Find the value of this expression if x =7
x² +6/x - 2

Answers

Answer: [tex]\frac{355}{7}[/tex]

Decimal Answer: 47.857143

Please Mark Me As Brainliest If I Helped. Have a Great Day :D

Will vote brainiest!!!! Please hurryy!!!!!! Have a great day!!!!! Hikgjorh

Answers

Answer:

a = - 1.1

Step-by-step explanation:

The condition for a single variable function f(x) to be decreasing is f'(x) < 0.

f(x) = 4/x^2 - 6x + 9

Then, differentiating with respect to x on both sides we get,

f(x) = 4(-2)(1/x^3) - 6 < 0

-8/x^3  - 6 < 0

8/x^3 + 6 > 0

{Dividing both sides with - 1 and hence the inequality sign changes}

8/x^3 > -6

8 > - 6x³ {Multiplying both sides with x³}

6x³ > - 8 {Interchanging the sides}

x^3 > -8/6

⇒ x > - 1.1

So,  a = - 1.1

Answer:

  a = 3

Step-by-step explanation:

The function can be written as ...

  f(x) = 4/(x -3)^2

This has a vertical asymptote at x=3 and will be decreasing for all values of x to the right of that -- on the interval (3, ∞).

  a = 3

A 16 -inch laptop has a screen that is 7 inches tall. How wide is the screen?

Answers

Answer:

Approximately 14.4 inches

Step-by-step explanation:

A 16-inch laptop means that a diagonal across the screen is 16 inches.

Imagine that the laptop is a triangle, with 2 sides: the height and the width of screen, and a hypotenuse, the diagonal across the screen (see attached image).

Here, we can use the Pythagorean theorem to find the width.

The relationship is the following

[tex]diagonal^2 = height^2 + width^2[/tex]

We can rearrange this to find the width of the screen:

[tex]diagonal^2 = height^2 + width^2\\diagonal^2 -height^2 = width^2\\width^2 = diagonal^2 -height^2\\width = \sqrt{diagonal^2 - height^2}[/tex]

Let's put in our values for the diagonal and the height:

Diagonal = 16

Height = 7

[tex]width = \sqrt{16^2 - 7^2}\\ width = \sqrt{256 - 49} \\width = \sqrt{207}\\width = 14.3874946[/tex]

As we can see, the width of our laptop is around 14.4 inches.

Answer: approximately 14.4 inches

The width of the laptop screen is x = 14.3inches.

Given that,

A 16 inch laptop has a screen that is 7 inches tall.

We have to determine,

How wide is the screen.

According to the question,

 Diagonal length of the laptop = 16 inches

Length of the laptop = 7 inches

Width of the laptop = x inches

By using Pythagoras theorem,

[tex](Diagonal)^2 = (length)^{2} +( width)^{2}\\\\(16)^2 = (7)^2 + x^{2} \\\\x^{2} = 256 - 49\\\\x^{2} = 207\\\\x = \sqrt{207}\\\\x = 14.38 \ inches[/tex]

Hence, The width of the laptop screen is x = 14.3inches.

To know about Measurement click the link given below.

https://brainly.com/question/17690582

Jan has 18 cards. Ray gives her v cards. Jan now has less
than 30 cards.
Which best describes Jan's cards?
a
y + 18 < 30

1 – 18 > 30
c
V - 18 < 30
Od
v + 18 > 30
Question 4 25 points)

Answers

Answer:

A. V + 18 < 30

Step-by-step explanation:

First of all, less than is the sign that points to the left,

Secondly, I'm guessing that y is actually V,

Before Ray gave Jan cards, she had 18,

so it is 18 plus V (the number of cards Ray gave her),

SO,

V + 18 < 30

solve 3(3x - 6) = 18

Answers

Steps to solve:

3(3x - 6) = 18

~Distribute left side

9x - 18 = 18

~Add 18 to both sides

9x = 36

~Divide 9 to both sides

x = 4

Best of Luck!

Answer:

x = 4

Step-by-step explanation:

Let's work on isolating (3x - 6).  Start by dividing both sides of 3(3x - 6) = 18 by 3, obtaining:

3x - 6 = 6.

Next, add 6 to both sides:

3x = 12

Finally, divide both sides by 3:

x = 4

-3/4x <12

show step by step

Answers

Answer: x<-1/4

Step-by-step explanation:

Given

-3/x<12

Multiply x on both sides

-3/x · x<12 · x

-3<12x

Divide 12 on both sides

-3 / 12 < 12x / 12

-1/4<x

one real world example of when we use rates and unit rates is _________.

Answers

In Sporting Events

Step-by-step explanation:

When comparing quantities you simplify which is your change fr the money you gave or your Tip you gave.

Answer:

Economics!

Step-by-step explanation:

I'll keep it brief, I'm in a class.

Say you're gain a certain amount of money, and losing some as well.

Find the difference, you got your rate, so you just graph it!

Stay Safe!

Select all the sums that are positive. A.–5 + (–2) B.5 + (–2) C.–3 + 4 D.0 + (–3) E.–2 + 4

Answers

Answer:

B and c and e

Step-by-step explanation:

Sorry if late I need points

The sums 5 + (–2), –3 + 4, and –2 + 4 are positive option (B), (C), and (E) are correct.

What is an arithmetic operation?

It is defined as the operation in which we do the addition of numbers, subtraction, multiplication, and division. It has a basic four operators that is +, -, ×, and ÷.

It is given that:

A.–5 + (–2)

= -5 + (-2)

= -5 - 2

= -7 (negative)

B. 5 + (–2)

= 5 - 2

= 3 (positive)

C. –3 + 4

= -3 + 4

= 1 (positive)

D. 0 + (–3)

= -3 (negative)

E. –2 + 4

= -2 + 4

= 2 (positive)

Thus, the sums 5 + (–2), –3 + 4, and –2 + 4 are positive option (B), (C), and (E) are correct.

Learn more about the arithmetic operation here:

brainly.com/question/20595275

#SPJ2

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