A water treatment plant needs to maintain the ph of the water in the
reservoir at a certain level. To monitor this, they take 2 oz. of water at 37
locations every hour, measure the ph at each of those locations, and find
their average. If the ph level of the reservoir is ok, the results at each
location will have varying results, with an average pH of 8.5 and a standard
deviation of 0.22. If the pH level of the reservoir is ok, what is the probability
that the sample average is LESS than 8.40?
0.9971
O 0.3264
• 0.0029
• 0.6736

Answers

Answer 1

Using the normal distribution and the central limit theorem, it is found that there is a 0.0029 = 0.29% probability that the sample average is LESS than 8.40.

Normal Probability Distribution

In a normal distribution with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the z-score of a measure X is given by:

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

It measures how many standard deviations the measure is from the mean. After finding the z-score, we look at the z-score table and find the p-value associated with this z-score, which is the percentile of X.By the Central Limit Theorem, the sampling distribution of sample means of size n has standard deviation [tex]s = \frac{\sigma}{\sqrt{n}}[/tex].

In this problem:

The mean is of [tex]\mu = 8.5[/tex].The standard deviation is of [tex]\sigma = 0.22[/tex].A sample of 37 is taken, hence [tex]n = 37, s = \frac{0.22}{\sqrt{37}} = 0.0362[/tex].

The probability that the sample average is LESS than 8.40 is the p-value of Z when X = 8.4, hence:

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

By the Central Limit Theorem

[tex]Z = \frac{X - \mu}{s}[/tex]

[tex]Z = \frac{8.4 - 8.5}{0.0362}[/tex]

[tex]Z = -2.76[/tex]

[tex]Z = -2.76[/tex] has a p-value of 0.0029.

0.0029 = 0.29% probability that the sample average is LESS than 8.40.

To learn more about the normal distribution and the central limit theorem, you can take a look at https://brainly.com/question/24663213


Related Questions

Ninja gym membership costs $33 per month after an initial membership fee. You paid a total of $338 after 5 months. Write an equation that gives you the total cost related to the months of your gym membership.

Answers

33x + 173 = total

To find this you have the equation 33x + m = 338. It tells us that this is after 5 months, so now we put 5 into x and multiply to get 165. Now the equation looks like 165 + m = 338. Subtract 165 from both sides to find m, which leaves us with 173 for the initial fee. Now you just have to rewrite the equation to be 33x + 173 = Total amount

Find the 70th term of the following arithmetic sequence.
13, 22, 31, 40,

Answers

its 31 just trust me homie;)

Answer:

634

Step-by-step explanation:

Nth term of an arithmetic progression is given by:

Tn=a+(n-1)d

Where 'Tn' is the Nth term of A.P. , 'a' is the first term of A.P. , 'n' is the no. of terms and 'd' is the common difference.

22-13=9, 31-22=9, 40-31=9.

So, d=9

a=13

n=70

Put the values in the Formula.

T70=13+(70-1)*9=13+69*9=13+621=634

are they congruent? 50 points please help ​

Answers

Answer:

Yes

Step-by-step explanation:

they were just dilated differently

Answer:

Yes

Step-by-step explanation:

The only difference is that they are dilated. And the dilation is the same from all sides.

Hope this helped!! :)

Stay safe and have a wonderful day/night!!!!!

Brainliest?!?!

A system of equations is shown below,

y = 5x + 2
10x - 2y = 12

what is the solution to the system of equations?

Answers

Answer: No solution
Step by step:
10x-2(5x+2)=12
10x-10x-4=12
0x=16
No solution

Find the value of the expression below for x = 3.

x2+ 5

A.8 B.11 C.14

Answers

Answer:

11

Step-by-step explanation:

Plz mark brainliest thanks

Find the circumference of a circle with a diameter of 6 cm. Leave your answer in terms of pi
9 pi cm
24pi cm
12pi cm
бpi cm

Answers

6 π cm-------------------------------

Step-by-step explanation:

diameter = 6cm

radius = diameter ÷ 2

= 6 ÷ 2

= 3cm

circumference = 2π × radius

= 2 π × 3cm

= 3π cm

-----------------------------FOLLOW ME

24 pack of mountain dew for 9.99 or a pack if mountain dew for 5.99 find the unit number​

Answers

Answer:

24 pack of mountain dew=9.99

1 pack of mountain dew=9.99/24=0.41625

Please tell me the answer and explain it too please!!!​

Answers

Answer:

56-8=48cm²

Step-by-step explanation:

area 1 (triangle area)=1/2bh

=1/2×4×4=8cm²

area 2(rectangle area)=lw

=8×7=56cm²

the shaded area=area 2-area 1

=56-8=48cm²

Anna wants to celebrate her birthday by eating pizza with her friends. For $42.50 total, they can buy p boxes of pizza. Each box of pizza costs $8.50.

Answers

Answer: they can get 5 pizzas

Step-by-step explanation:

42.50 divided by 8.50 is 5

Answer:

They can buy 5 pizzas.

Step-by-step explanation:

HELP PLEASE
(Look at the picture)

Answers

Answer:

D is correct (I think).

Step-by-step explanation:

A and C are completely invalid, as A is a linear function and C does not go up in intervals of 25.

Answer C is a linear function and is represented by y=x+1, but there are potential other reasons that it could be considered a linear function.

Answer D cannot be solved by y=mx+b because it is an exponential function.

PLEASE HELP!!!!!! ILL GIVE BRAINLIEST *EXTRA 40 POINTS** !! DONT SKIP :((

Answers

Answer: im in 100% sure but i think its yes

Step-by-step explanation:

Answer:

No

Step-by-step explanation:

I used photomath

Which sentence best describes the main idea of a text?

A.) It states the author's opinion about a different topic.

B.) The important details in the text support it.

C.) It can stand by itself without any need for support.

D.) It always appears in the title of the text.

Answers

Answer: B

Step-by-step explanation:

I am not sure if this is correct but this is probably the most likely answer

If a⋅b+c⋅d=12, and a,b,c and d are all integers greater than 1, how many values are possible for a, if a, b, c, and d are not necessarily distinct?

Answers

Answer:

hajajhagshausuwuw8h1v2os q

the price of a stereo system is $627.50 the sales tax is 6% find the amount of the tax and the total cost ​

Answers

the answer for the tax is 37.65 you do the rest :)

Which word best describes the degree of overlap between the
two data sets?

Low
high
none
moderate

Answers

Answer:

moderator since the lines are similar

hope it helps <3!

Step-by-step explanation:

100% correct

The overlap between both data sets can best be described as being moderate.

What is the degree of overlap between both sets?

The degree of overlap shows the pairwise distance that can be observed between the variables in both data sets.

The degree of overlap above can be said to be moderate because the pairwise distance isn't too different.

Find out more on degree of overlap at https://brainly.com/question/1289628.

#SPJ2

An item is regularly priced at $51 . It is on sale for 35 %off the regular price

Answers

Answer:

17.85$

Step-by-step explanation:

if the expression (2x^4)^3 was written in ax^b form, which of the following would be the sum of a and b

Answers

Answer:20

Step-by-step explanation:

4(n+2)-2n=0
Distributive property

Answers

Answer:

n=-4

Step-by-step explanation:

Bob gets paid an annual salary of $30,000 and earns 5% commission on all sales he makes. If Bob wants to make $6,000 this month, how much in sales does he need to have?
a.
$50,000
b.
$70,000
c.
$90,000
d.
$120,000

Answers

Answer:

The answer is 70,000 sales.

Bob gets paid an annual salary of $30,000, which means that monthly he gets:

$30,000 : 12 months = $2,500 per month

x - number of sales

Bob earns 5% commission on all sales he makes: x * 5% = x * 0.05 = 0.05x

The function is:

f(x) = 2,500 + 0.05x

Bob wants to make $6,000 this month: f(x) = 6,000

2500 + 0.05x = 6000

0.05x = 6000 - 2500

0.05x = 3500

x = 3500 : 0.05

x = 70000 sales

Step-by-step explanation:

Sales for the month should amount to $70,000

Annual salary = $30,000

Commission on sales = 5%

To make 6000 in a month :

Monthly salary = $30000 / 12 = $2500

Month earning = $2500 + 5% × (monthly sales)

Month earning = $6000

Let month sales = m

6000 = 2500 + 0.05m

6000 - 2500 = 0.05m

3500 = 0.05m

m = 3500 / 0.05

m = 70,000

Sales for the month should be 70,000

Learn more : https://brainly.com/question/18112348

I GIVE BRAINLIEST FOR EXPLANATION AND CORRECT ANSWER EXTRA POINTS 3

Answers

Answer:

[tex]x=8[/tex]

Step-by-step explanation:

The best way to go about this is to use a trig identity. You have the unknown opposite the angle and the hypotenuse, so its best to use the sine identity: [tex]sin(x)=\frac{O}{H}[/tex], where O is the opposite side, and H is the hypotenuse.

Set up the equation as:[tex]sin(27)=\frac{x}{17}[/tex], and solve for X.

I got x=7.718, rounded to x=8.

If I helped, a brainliest answer would be greatly appreciated!

Tasty Treats Baking Company asked all students in the senior class at Ridgemont High School the question, “Do you prefer chocolate or butterscotch Tasty Treats?” Everyone surveyed had to pick one of the two answers, and 42%, percent said they preferred chocolate.
Based on this data, which of the following conclusions are valid?

Answers

Answer:

42%, percent of all students in the senior class at Ridgemont High prefer chocolate.

Step-by-step explanation:

Answer:

42%, percent of all students in the senior class at Ridgemont High prefer chocolate.

Step-by-step explanation:

your answer awaits:

In ΔDEF, the measure of ∠F=90°, the measure of ∠D=67°, and FD = 7.4 feet. Find the length of EF to the nearest tenth of a foot.

Answers

Answer:

14.2 ft

Step-by-step explanation:

tan 66° = 32/ FD

FD = 32 / tan 66° = 32 / 2.246 = 14.2

hope it helped you

Answer:

17.4

Step-by-step explanation:

\tan D = \frac{\text{opposite}}{\text{adjacent}}=\frac{x}{7.4}

tanD=

adjacent

opposite

=

7.4

x

\tan 67=\frac{x}{7.4}

tan67=

7.4

x

7.4\tan 67=x

7.4tan67=x

Type into calculator and round to the nearest tenth of a foot.

Bill is 6 years older than Mary. The sum of their ages is 48. What are the equations used to find their ages?

Answers

Step-by-step explanation:

Mary's age = x

Billi's age = x+6

So, Mary age + Billi age = x + (x + 6)

Sum of their ages = 2x + 6

So, 2x + 6= 48

2x = 48 - 6

2x = 42

x = 42/2

Mary age = x = 21

And Billi age = x +6= 21 + 6 = 27

So Mary = 21

And Billi = 27

Lets check!

21 + 27 = 48

So therefore their ages add up to 48

So the answer is correct!

Solve for u. 3u=7.5 please help me

Answers

Answer:

2.5

Step-by-step explanation:

7.5 divided by 3 equals 2.5.

(Also next time you can use a calculator)

The answer is U=2.5 it is 2.5 hope this helps you out.


The measurements of a rectangular room, in a scale drawing, are 2 inches by 3
inches. The scale is inch = 3 feet. If carpet costs $1.75 per square foot, how much will
it cost to put carpet in this room?

Answers

Answer:

so,

the room (2×3) × (3×3) feet, or 6x9 feet.

6x9= 54square feet

54 x 1.75= $94.50

There is a bag with only red marbles and blue marbles.
The probability of randomly choosing a red marble is 7/9.
There are 42 red marbles in the bag and each is equally likely to be chosen.
Work out how many marbles in total there must be.

Answers

Answer:

do 7/9*42. then you will get answer

Probability helps us to know the chances of an event occurring. The total number of red marbles in the bag is (7×42)/9.

What is Probability?

Probability helps us to know the chances of an event occurring.

[tex]\rm Probability=\dfrac{Desired\ Outcomes}{Total\ Number\ of\ outcomes\ possible}[/tex]

Given that there are 42 red marbles in the bag and each is equally likely to be chosen. Also, The probability of randomly choosing a red marble is 7/9. Therefore, the total number of red marbles in the bag is,

Number of red marbles = 7/9 × 42

Learn more about Probability:

https://brainly.com/question/795909

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Tanveer bought 0.7 pounds of sliced ham at his local deli. If the deli charged $6.79 per pound, how much did Tanveer pay?
$2.04
$4.75
$7.49
$9.70
Mark this and return

Answers

Answer:

Total amount of money paid by Tanveer at his local deli = $4.75

Step-by-step explanation:

Quantity of sliced ham bought by Tanveer at his local deli = 0.7 pounds

Amount of money charged by deli per pound of ham = $6.79

Now, we need to find the total amount of money paid by Tanveer at his local deli for buying the 0.7 pounds of sliced ham.

So, Total amount of money paid by Tanveer at his local deli = Quantity of sliced ham bought × Price of ham per pound

⇒ Total amount of money paid by Tanveer at his local deli = 6.79 × 0.7

⇒ Total amount of money paid by Tanveer at his local deli = $4.75

Answer:

Total amount of money paid by Tanveer at his local deli = $4.75

Step-by-step explanation:

How would you describe the correlation in the data? Explain your reasoning.

Answers

Answer:

Where is the options

Step-by-step explanation:

Answer: sorry where's the pic?

Step-by-step

Raul ate 7/8 of 1/2 a pizza. How much of the pizza did Raul eat?

Answers

Answer:

7

16

Step-by-step explanation:

7/8× 1/2=

7 × 1

8 × 2

=7/16

4.5% of what number is 99?​

Answers

Answer:

2200

Step-by-step explanation:

4.5% × ? = 99

? =

99 ÷ 4.5% =

99 ÷ (4.5 ÷ 100) =

(100 × 99) ÷ 4.5 =

9,900 ÷ 4.5 =

2,200

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