Salaries for teachers in a particular elementary school district are normally distributed with a mean of $41,000 and a standard deviation of $7,200. We randomly survey ten teachers from that district. (Round your answers to the nearest dollar.)
(a) Find the 90th percentile for an individual teacher's salary.
$


(b) Find the 90th percentile for the average teacher's salary.
$

Answers

Answer 1

Using the normal distribution and the central limit theorem, it is found that:

a) The 90th percentile for an individual teacher's salary is $50,216.

b) The 90th percentile for the average teacher's salary is $43,914.

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 given by [tex]s = \frac{\sigma}{\sqrt{n}}[/tex].

In this problem:

Mean of $41,000, thus [tex]\mu = 41000[/tex].Standard deviation of $7,200, thus [tex]\sigma = 7200[/tex].

Item a:

The 90th percentile is X when Z has a p-value of 0.9, so X when Z = 1.28. Thus:

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

[tex]1.28 = \frac{X - 41000}{7200}[/tex]

[tex]X - 41000 = 1.28(7200)[/tex]

[tex]X = 50216[/tex]

The 90th percentile for an individual teacher's salary is $50,216.

Item b:

Average for a sample of 10, thus [tex]n = 10, s = \frac{7200}{\sqrt{10}}[/tex].

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

By the Central Limit Theorem

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

[tex]1.28 = \frac{X - 41000}{\frac{7200}{\sqrt{10}}}[/tex]

[tex]X - 41000 = 1.28\frac{7200}{\sqrt{10}}[/tex]

[tex]X = 43914[/tex]

The 90th percentile for the average teacher's salary is $43,914.

A similar problem is given at https://brainly.com/question/24663213


Related Questions

I am thinking of two numbers.
Sum of these two numbers
is 58, and the difference of these two numbers are b.
What are the two numbers?
What is the answer to this problem?

Answers

Answer:

Step-by-step explanation:

Let one number=x

Therefore the othernumber=x+b

Since,

    x+x+b=58

==>2x+b=58

==>2x=58-b

==>x=(58-b)/2

Therefore the other number is (58-b)/2   + b

Jayden needs at least 3 cups of vegetable oil to make chow menu. If Jayden has 20 fluid ounces of vegetable oil , and there are 8 fluid ounces in 1 cup will he be able to make chow mein . Yes or no

Answers

Answer: No

Step-by-step explanation:

He need 3 cups which is converted into 24 ounces. There is 8 ounces in a cup and he has three. He has 20 ounces and he needs 24.

Help me on this pls and thank you

Answers

y=8x+0

the 0 is where the y intercept is, here it goes through the origin (0,0) so it isn’t necessary to write it but it helps recognize what it does
the 8x is the slope, it goes over one and up 8 each time (each line on the y axis is worth 4, so even though it goes up 2 boxes it goes up 8 total points)

)) Jerry took his extended family out for a dinner that cost $480. Jerry paid 5% sales tax
and left a 20% tip on $480. What was the total cost?

Answers

Answer:

$600

Step-by-step explanation:

Evaluate each function for the given input values. For f (x)=2/3x+ 3, find f (x) when x= 9 and when x=-3

Answers

Answer:

Step-by-step explanation:

f(x) = 2/3 x + 3

x = 9

f(9) = 2/3 * 9 + 3            Divide 9 by 3

f(9) = 2 * 3 + 3               Combine 2 * 3

f(9) = 6 + 3                    Combine

f(9) = 9                          The answer is just a coincidence. The answer for the next one shouldn't be - 3

f(-3) = 2/3 *(-3) + 3         Divide 3 into - 3

f(-3) = 2*(-1) + 3

f(-3) = -2 + 3

f(-3) = 1

How was this done?

You should observe that whatever value you see on the left in the brackets, appears where the x is on the right. This is a very important concept. You should do your best to understand it because algebra is sort of based on it.

In preparation for her math test on Thursday, Emerson studied 1/2 hour on Monday, 1 1/16 hours on Tuesday, and 3/8 hour on Wednesday. What is the total amount of time that Emerson spent studying for her test? (Simplify your answer and state it as a mixed number.)

Answers

Answer:

Step-by-step explanation:

1/2 + 1 1/16 + 3/8 = ?

Least common denominator is 16

8/16 + 17/16 + 6/16 = 31/16 = 1 15/16 hours

A street sign is in the shape of an isosceles triangle that has a base of 6.5 inches bigger than either of the equal sides. If the perimeter of the triangle is 65 inches, what is the length of the equal sides?

Answers

Answer:

19.5

Step-by-step explanation:

side is 6.5 bigger, so minus the 6.5 from the total perimeter of 65 and divide by 3.

65- 6.5 = 58.5

58.5 ÷ 3 = 19.5

equal sides are 19.5

longer side is 19.5 + 6.5

Answer:

19.5 inches

Step-by-step explanation:

You can interpret this problem as x + x + (x + 6.5)=65, with x being the length of the equal sides.

Simplified, this equation becomes 3x+6.5=65.

Solving, this becomes 3x+6.5-6.5=65-6.5 which comes out as 3x=58.5. Next, we divide this equation by 3 on both sides, which then comes out to x=19.5. Therefore, the length of equal sides are 19.5.

Check: There are two equal sides, so 19.5+19.5. Since the base is 6.5 inches bigger than either of the equal sides, the base is equal to 19.5+6.5=26. Adding these values all together comes out to 19.5+19.5+26=65.

Oliver drove the first 90 miles of his journey in 1.5 hours and the remaining 120 in 3 hours. What was the average speed on the second part of Oliver’s journey?

Answers

Answer:

Step-by-step explanation:

90 miles + 120 miles = 210 total miles

1.5 hours + 3 hours = 4.5 total hours.

Average speed = 210 miles / 4.5 hours = 46 2/3 miles per hour

Answer:

40

Step-by-step explanation:

I know meth

Suppose a supplier estimate that a new products will generate the following revenue stream. period. revenue year 0= 0 year 1=$62500 year 2 =$89 400 year 3=$ 136 200 year4 =$ 128300 year5=$ 112000 If the required rate of return is 11%, determine the value of all these cash flows at year 2.​

Answers

Answer:

9834

Step-by-step explanation:

11*100*89400.

What is 1/3 - 1/7 = ?

Answers

(1/3) - (1/7) = 4/21

Answer:

[tex]\frac{4}{21}[/tex]

Step-by-step explanation:

In order to find the answer you need to find the common denominator of the two fractions multiply the fractions to receive that common denominator and then subtract to find your answer.

[tex]\frac{1}{3} -\frac{1}{7}[/tex]

Find the common denominator:

[tex]CD=21[/tex]

[tex]1\times7=7[/tex]

[tex]3\times7=21[/tex]

[tex]=\frac{7}{21}[/tex]

[tex]1\times3=3[/tex]

[tex]7\times3=21[/tex]

[tex]=\frac{3}{21}[/tex]

[tex]\frac{7}{21} -\frac{3}{21}[/tex]

Subtract numerators

[tex]7-3=4[/tex]

[tex]=\frac{4}{21}[/tex]

Hope this helps.

NO LINKS PLEASE HELP DUE IN 10MINS!While making oatmeal cookies, Angela needs to add cup of milk to her dough. However, she has only a -cup measuring cup. How many times does she need to fill the measuring cup to pour cup of milk?
The number of times Angela needs to fill the -cup measuring cup to pour cup of milk is

Answers

Answer:15

Step-by-step explanation:

Is y=-x^3+2x linear or non linear

Answers

9514 1404 393

Answer:

  non-linear

Step-by-step explanation:

The degree of this polynomial equation is the highest power of x: 3. When the degree is not 0 or 1, the relation is non-linear.

You want to buy a shirt that is $11.99 and the store is having a 25% off sale what do u pay for the shirt

Answers

It is 25% off so it is 75% of the price. 75/100*11.9 = 8.9925

It rounds to about $8.99

You would pay 8.99 for the shirt. You would do this because you first multiply 11.99 by 0.75 because 1.00-0.25=0.75, when you do this you end up with 8.9925 and because this is money you round to the nearest hundred, giving you the answer, 8.99.

Brainlist for you :)​

Answers

Answer:BAHAHAHA THATS AWESOME

Step-by-step explanation:

Simplify Forty eight fourths 48/4

Answers

The answer should be 12!
48 divided by 4 is 12:)

Step-by-step explanation:

48 divided by 4, is 12

or 12/1

You have three pieces of ribbon measuring 16 cm, 24 cm, and 40 cm respectively. You want to cut them into strips of the same length. What is the longest possible length of one strip?

Answers

What do you mean by ”What is the longest possible length of one strip?”

Answer:8

Step-by-step explanation:

(16---->1,2,4,(8),16

24----->1,2,3,4,6,(8),12,24

40----->1,2,4,5,(8),10,20,40

Because 8 is the largest common divisor

A deep sea diver dives 26 feet from the surface of the ocean. He then ascends 7 feet. What interger represents the divers present location in the sea?

Answers

Answer:

-19

Step-by-step explanation:

Previous position in sea + change in position= current position

-26+7= -19

Hope this helps! :)

Answer:

It is -19

Step-by-step explanation:

Well, you would do this -26 + 7 because the diver dove 26 feet BELOW sea level, which is also -26. He then ascends 7 feet, which means he is coming UP. So -26 + 7 = -19.

Help help help plz plz

Answers

Answer:

6^15

Step-by-step explanation:

please mark me as brainlest

Snoopy the dog is on a 25-ft long chain that is attached to the back of a barn (see the
picture below). If the chain does not allow him to go past either of the adjacent sides
of the barn, how much space does Snoopy have to roam?
Use pi = 3.14 and round your answer to the nearest tenth.

Answers

Answer:

A   = 981.3 ft^2

Step-by-step explanation:

Here we're calculating the area of a semicircle of radius 25 ft.

The area of a circle is A = (pi)(r)^2, and that of a semicircle of the same radius is A = (1/2)(pi)(r)^2.

Here pi = 3.14 and r = 25 ft, and so the area/space in question is

A = (1/2)(3.14)(25)^2

A   = 981.3 ft^2

The space does Snoopy have to roam is 490.625 square feet.

Given that, Snoopy the dog is on a 25-ft long chain that is attached to the back of a barn.

What is the area of a sector?

The area of a sector is the space inside the section of the circle created by two radii and an arc. It is a fraction of the area of the entire circle.

The formula for the area of the sector of a circle is /360° (r²) where r is the radius of the circle and is the angle of the sector.

From the attached image, we see that snoopy is at the edge of a circle with the garage taking up a quarter of that circle.

Now, the area of space Snoopy was roaming

= 90°/360° × (3.14 × 25²)

= 1/4 × (3.14 × 625)

= 0.25 × 1,962.5

= 490.625 square feet

Therefore, the space does Snoopy have to roam is 490.625 square feet.

To learn more about the area of a sector visit:

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I NEED A 100% ACCURATE ANSWER FOR THIS QUESTION ASAP NO LINKS !!!

Answers

Answer:

Infinitely many solutions

Step-by-step explanation:

6x+18=2(3x+9)

6x+18=6x+18

Since both sides are equal to each other, then there are infinitely many solutions because no matter what x is, both sides will be equal to each other.

Answer:

infinite many solutions, (C)

Step-by-step explanation:

Once you distribute you get 6x+18 on both sides. Meaning that the answer is this has infinite many solutions.

Can I have brainliest? It would help me out, if not thanks anyways! Hope this helped and have a nice day!

100 POINTS!!! & Brainliest


A cat weighing 12.1lb needs insulin at 2.0 international units (IU)/kg. The insulin comes in a concentration of 10 IU/mL. How much insulin do you give the cat? Please show work!

Answers

Answer:

[tex]1 \: lb = 0.453 \: kg \: \\ first \: lb \: convert \: to \: kg \\ cat \: weight \: 12.1 \times 0.453 = 5.4813 \: kg \\ how \: much \: iu \: isulincat \: need \\ we \: must \: multiply\: the \: weight \: of \:cat \: to \: 2 \\ \\ 5.4813 \times 2 = 10.9626 \: iu[/tex]

good luck

The path of a skateboarder can be modeled by the equation (x – 3)2 = –4(y – 9), where distance is in feet and air resistance is insignificant. If the skateboarder makes a jump from a ramp at x = 0, what is her maximum height and how far is she horizontally from the end of the ramp when she lands?

Answers

Answer:

The correct answer would be: "Maximum height 9 feet; horizontal distance 9 feet".

Step-by-step explanation:

I know this not only because I already took the test, BUT by graphing the equation (you can use graphing apps) it'll give you the answer.

Her maximum height is 9 feet & she is horizontally 9 feet from the end of the ramp when she lands.

What is skateboarders maximum height ?

The path of the skateboarder can be modelled by the equation,

(x-3)² = -4(y-9)

Now, from the equation, solving y,

(x-3)² = -4(y-9)

⇒ y-9 = -[tex]\frac{1}{4}[/tex](x-3)²

⇒ y = -[tex]\frac{1}{4}[/tex](x-3)² + 9

∴ Maximum height is 9 feet.

How far is she horizontally from end of ramp ?

We have to take y = 0,

Now, -[tex]\frac{1}{4}[/tex](x-3)² + 9 = 0

        ⇒ -(x²-6x+9)+36 = 0

        ⇒ -x²+6x-9+36 = 0

        ⇒  x²-6x-27 = 0

        ⇒ x²-9x+3x-27 = 0

        ⇒ (x-9)(x+3) = 0

        ⇒ x = 9 or x = -3

Neglecting the negative value we get, x = 9

So, Her horizontal distance from end of the ramp is 9 feet.

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Is the number zero 0 an integer?

Answers

Yep! It is an integer!

Any negative, positive number or 0 is an integer.

Hope it helps!

0 is an integer

an integer is simply any number that does not have a decimal point and is not a fraction.

even of it has a negative sign or positive sign, it is still an integer

it can also be called a whole number

hope this helps,

thank you!!

Given N1 = 6 and Nn+1 = 6(Nn - 4) ). Find N3.​

Answers

Answer:

48

Step-by-step explanation:

N₁ = 6

N(n+1) = 6*(Nn  -4 )

N₍₁₊₁₎= 6* (N₁ - 4)

N₂ = 6 *(6-4)  = 6*2

N₂ = 12

     N₍₂₊₁₎ = 6*(N₂ - 4)

      N₃ = 6*(12 -4) = 6* 8

     N₃ = 48

Please help me understand

Answers

Answer:

C. $30

Step-by-step explanation:

According to the first part of the equation, hourly pay is $25, up to 38 hours.

Overtime is paid over 38 hours.

Find the hourly pay for overtime, taking x = 39 and finding the difference with the total at x = 39 and x = 38, then we have the payment for one hour.

30(39 - 38) + 950 - 38*25 = 30 + 950 - 950 = 30

Correct choice is C

Can someone help me and explain me how you do this and not only give me the answer?

Answers

Answer:

just add the terms -154+8850= 8696 m

Katy is older than Alex and Beth. Sarn is
younger than Alex and older than Beth.
Delores is older than Sam but younger than
Katy. Delores is Alex's older sister. If the
ages of these students are 14, 15, 16, 17,
and 18, who is 16 years old?

Answers

This would be Delores because it goes katy, Delores, Alex, Sam, Beth

what's the answer for this?​

Answers

9514 1404 393

Answer:

  x = (y +2)/3

Step-by-step explanation:

The flowchart is trying to help you see that you "undo" what is done to x, in reverse order.

  x is first multiplied by 3, then -2 is added.

First, we want to undo the addition of -2, so we add the opposite of that to y:

  y = 3x -2   ⇒   y +2 = 3x

Then we want to undo the multiplication by 3, so we divide by 3:

 y +2 = 3x   ⇒   (y +2)/3 = x

The solution for x is ...

  x = (y +2)/3

_____

Additional comment

In your diagram, each box has the inverse operation of the one in the box above it. The inverse of subtracting 2 is adding 2. The inverse of multiplying by 3 is dividing by 3. The arrows connecting the boxes are intended to show you that these inverse operations occur in the reverse order of the original operations, as we described above. (The small box at bottom center might contain "3x".)

Triangle A, B, C, is shown. Angle C, A, B is 70 degrees. Angle A, B, C is 70 degrees.
Find the missing angle A C B

Answers

Answer:

40°

Step-by-step explanation:

<CAB=70°

<ABC=70°

<ACB+ <CAB+ <ABC=180(sum of angles in a triangle)

<ACB +70+70=180

<ACB+140=180

<ACB=180-140

<ACB=40°

Help pls? Thank you! I suck at time......

Answers

Answer:

20 minutes after 3:00

Step-by-step explanation:

Answer:

The answer would be 20 minutes after 3:00

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