A teacher gives her class a particular examination on mathematics at the end of each year. The results are normally distributed with a mean test score of 60 and a standard deviation of 8. The teacher has told the class that students with a test score in the top 2.5% will win a special prize. Calculate the test score above which 2.5% of all test scores lie. Give your answer to 1 decimal place. Test score

Answers

Answer 1

Answer:

Test score of 75.7.

Step-by-step explanation:

Problems of normal distributions can be solved using the z-score formula.

In a set with mean \(\mu\) and standard deviation \(\sigma\), the zscore of a measure X is given by:

\(Z = \frac{X - \mu}{\sigma}\)

The Z-score 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. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.

The results are normally distributed with a mean test score of 60 and a standard deviation of 8.

This means that \(\mu = 60, \sigma = 8\)

Calculate the test score above which 2.5% of all test scores lie.

Above the 100 - 2.5 = 97.5th percentile, which is the value of X when Z has a pvalue of 0.975, so X when Z = 1.96.

\(Z = \frac{X - \mu}{\sigma}\)

\(1.96 = \frac{X - 60}{8}\)

\(X - 60 = 8*1.96\)

\(X = 75.7\)

Test score of 75.7.


Related Questions

Convert 0.622 0.622 to a fraction in simplest form and a percent.

Answers

Answer: 311/500 and 62.22%

Step-by-step explanation:

Fraction: 0.622 = 622/1000 = 311/500

Percent: 0.6222 = 62.22 % (Move decimal 2 places down)

The decimal 0.622 in the form of simplest fraction as 311/500 and in percent is 62.2%.

To convert 0.622 to a fraction in simplest form, write it as follows:

0.622 = 622/1000

Now, simplify this fraction by dividing both the numerator and the denominator by their greatest common divisor, which is 2:

622/1000 = (311 × 2)/(500 × 2)

                 = 311/500

So, 0.622, when expressed as a fraction in simplest form, is 311/500.

To convert 0.622 to a percent, multiply it by 100:

0.622 × 100 = 62.2%

Therefore, 0.622 is equivalent to 311/500 or 62.2%.

Learn more about Percentage here:

https://brainly.com/question/32197511

#SPJ6

4. The price of a Dell laptop is d dollars. Ramsey makes a 10% down payment for atwo-year installment purchase. The monthly payment is m dollars. Express thefinance charge algebraically. *A.0.10d(24)mB.24m - 1.10C.24m(.10d)D.024m - 100

Answers

should be 0.10d - 24(m)

A certain drug is eliminated from the bloodstream exponentially with a half-life of 12 hours. Suppose that apatient receives an initial dose of 25 milligrams of the drug at midnight. Estimate when the drugconcentration will reach 20% of its initial level. Round the answer to the nearest whole number.

Answers

Determine 20% of the initial level

20% → 0.2

\(25\text{ mg}\cdot0.2=5\text{ mg}\)

Write the equation with half-life of 12 hours and initial dose of 25 mg.

\(y=25\cdot\Big(\frac{1}{2}\Big)^{\frac{t}{12}}\)

Substitute y = 5, and solve for t

\(\begin{gathered} y=25\cdot\Big{(}\frac{1}{2}\Big{)}^{\frac{t}{12}} \\ 5=25\cdot\Big{(}\frac{1}{2}\Big{)}^{\frac{t}{12}} \\ \frac{5}{25}=\frac{\cancel{25}\cdot\Big{(}\frac{1}{2}\Big{)}^{\frac{t}{12}}}{\cancel{25}} \\ \frac{1}{5}=\Big{(}\frac{1}{2}\Big{)}^{\frac{t}{12}} \end{gathered}\)

Get the natural logarithm of both sides

\(\begin{gathered} \ln \frac{1}{5}=\ln \Big{(}\frac{1}{2}\Big{)}^{\frac{t}{12}} \\ \ln \frac{1}{5}=\frac{t}{12}\cdot\ln \Big{(}\frac{1}{2}\Big{)}^{} \\ t=\frac{12\ln \frac{1}{5}}{\ln \frac{1}{2}} \\ t=27.86313714 \end{gathered}\)

Rounding the answer to the nearest whole number, the time it takes for the initial dose to be reach 20% of its initial level is 28 hours.

Solve and graph
3x + 9 < 30

Answers

Answer: X<7

Step-by-step explanation:

3x+9<30

-9       -9

3x<21

/3    /3

X<7

Jon earns $3 for every package he wraps. To take a package to the post office, Jon earns 1.65 times as much as he earns for wrapping a package. How much will Jon earn for wrapping a package and taking it to the post office?

Answers

Answer:

a1 = 1, a2 = 2Step-by-step explanation:

y
4
Solve for y.
Then, find the side lengths of the
largest triangle.
Fill in the green blank.
8
X
2
+
2
8
y
y
[?]
X
Enter
Help
Skip

y4Solve for y.Then, find the side lengths of thelargest triangle.Fill in the green blank.8X2+28yy[?]XEnterHelpSkip

Answers

Answer:

y = 4\(\sqrt{5}\) , ? = 10

Step-by-step explanation:

using Pythagoras' identity on the smallest right triangle

x² = 4² + 2² = 16 + 4 = 20 ( take square root of both sides )

x = \(\sqrt{20}\) = \(\sqrt{4(5)}\) = \(\sqrt{4}\) × \(\sqrt{5}\) = 2\(\sqrt{5}\)

using Pythagoras' identity on the middle right triangle

y² = 8² + 4² = 64 + 16 = 80 ( take square root of both sides )

y = \(\sqrt{80}\) = \(\sqrt{16(5)}\) = \(\sqrt{16}\) × \(\sqrt{5}\) = 4\(\sqrt{5}\)

using Pythagoras' identity on the largest right triangle

?² = x² + y² = (2\(\sqrt{5}\) )² + (4\(\sqrt{5}\) )² = 20 + 80 = 100

Take square root of both sides

? = \(\sqrt{100}\) = 10

XYZ + 8P = 11
please help ​

Answers

Answer:

y=(11-8p)xz

Step-by-step explanation:

xyz+8p=11

xyz=11-8p

y=(11-8p)xz

Which expression is equivalent to (2.9)4? HELP ASAP

Which expression is equivalent to (2.9)4? HELP ASAP

Answers

Answer:

2^4   * 9^4

Step-by-step explanation:

(2*9)^4

We can take the power to each term inside the parentheses

2^4   * 9^4

We have 2 squares. One square is shaded 2/12 and the other shaded square in the diagram is 2/15 shaded. How much of the total diagram is shaded?

A.0.148
B.0.148 repeated
C. 0.3
D.0.3 repeated

Answers

By answering the presented question, we may conclude that In decimal form, the answer is 0.15, which is close to option A, 0.148. As a result, the answer is A. 0.148.

what is a square?

According to Euclidean geometry, a square is an equilateral quadrilateral having four equal sides and four equal angles. It is often referred to as a rectangle with two nearby sides of equal length. A square is an equilateral quadrilateral because it has four equal sides and four equal angles. Square angles are 90-degree or straight angles. Also, the diagonals of the square are evenly spaced and divide at a 90-degree angle. an adjacent rectangle with two equal sides. a quadrilateral with four equal-length sides and four right angles. A parallelogram with two adjacent, equal sides forming a right angle. A rhombus with straight sides.

To determine the answer, multiply the areas of the shaded squares by the overall area of the figure.

Assuming that both squares are the same size, we may combine the fractions using a common denominator:

2/12 + 2/15 = 5/60 + 4/60 = 9/60 = 3/20

As a result, the entire shaded area is 3/20 of the total area of the diagram.

We can't discover the exact area of the graphic because it's not presented. As a result, we can only represent the answer in fractions or decimals.

In decimal form, the answer is 0.15, which is close to option A, 0.148. As a result, the answer is A. 0.148.

To know more about square visit:

https://brainly.com/question/14198272

#SPJ1

The volume of a cylinder is 637 cm³. If the radius is 3 cm, what is the height
of the cylinder?

The volume of a cylinder is 637 cm. If the radius is 3 cm, what is the heightof the cylinder?

Answers

If the radius is 3 cm, the height of the cylinder is approximately 7.06 cm, which is closest to option B, 7 cm. The correct option is B.

The formula for the volume of a cylinder is V = πr²h, where V is the volume, r is the radius, and h is the height.

We are given that the volume of the cylinder is 637 cm³ and the radius is 3 cm. Substituting these values into the formula, we get:

637 = π(3²)h

Simplifying:

637 = 9πh

h = 637 / (9π)

h ≈ 7.06

Thus, the height of the cylinder is approximately 7.06 cm, which is closest to option B, 7 cm.

For more details regarding volume, visit:

https://brainly.com/question/1578538

#SPJ1

Lines p and q are parallel. Which are the angle measures of

Answers

i think p is he p he and he

Ms. Nutchern uses 145 beans (or 50% of the can) to make a pot of chili. How many beans are in the
Can

Answers

Answer: 290 beans

Step-by-step explanation:

You multiply 145 by 2 since 145 is half of the beans or do 145 divided by 1/2.

145 * 2 = 290.

145/.5 = 290

Hope this helps!!! :)

what is equivalent to 5x + 8y + 2

Answers

Answer:

(5 · x) + (8 · y) + (2 · 1)

Answer:

5x + 2 ( 4y + 1 )

Step-by-step explanation:

i just factorised 8y + 2

A quality control expert at LIFE batteries wants to test their new batteries. The design engineer claims they have a variance of 2916 with a mean life of 518 minutes.

If the claim is true, in a sample of 81 batteries, what is the probability that the mean battery life would be less than 526.4 minutes? Round your answer to four decimal places.

Answers

The probability that the mean battery life would be greater than 526.4 minutes if in a sample of 81 batteries having a variance of, 2916 and a mean life of 518 minutes is 0.0808.

What is probability?

The ratio of good outcomes to all possible outcomes of an event is known as probability. A lot of successful results for an experimental with 'n' results can be represented by the symbol x.

Given:

The variance = 2916,

The mean life of a battery, m = 518 min,

The total number of samples, n = 81

Calculate the probability of a mean battery life of lower than 526.4 minutes by the following formula,

z = x - m / (σ / √ n)

Here, x is the expected value, σ is the deviation, and z is the probability.

Substitute the values,

z = 526.4 - 518 / (54 / √81)         [σ = √ variance = √2916  = 54]

z = 1.4

Consult the cumulative standard normal table

P (z < 526.4) = 0.9192,

But we know that

P (z > 526.4) = 1 - P (z < 526.4)

P (z > 526.4) = 1 - 0.9192 = 0.0808

Therefore, The probability that the mean battery life would be greater than 526.4 minutes if in a sample of 81 batteries having a variance of, 2916 and a mean life of 518 minutes is 0.0808.

To know more about probability:

https://brainly.com/question/743546

#SPJ1

Round to the place value of the underline digit 372,297 underline digit is 7

Answers

The number would be 370,000

In the given statement is:
Round to the place value of the underline digit 372,297 underline digit is 7

Now, According to the question:

372,297

Place Value of first 7 = 70000

Place value of second 7 = 7

As 7 is in ten thousand place so after rounding we get,

370,000

Therefore, the number would be370,000

Learn more about Place value at :

https://brainly.com/question/1650658

#SPJ1

Help with the following equation 8x²-6x-5=x

Answers

Answer:

\(8 {x}^{2} - 6x - 5 = x\)

\(8 {x}^{2} - 7x - 5 = 0\)

x = (7 + √((-7)^2 - 4(8)(-5)))/(2×8)

= (7 + √(49 + 160))/16

= (7 + √209)/16

= -.4661, 1.3411 (to 4 decimal places)

PLEASE I NEED HELP

Use composition to prove that f(x) and g(x) are inverses. Check your work

PLEASE I NEED HELPUse composition to prove that f(x) and g(x) are inverses. Check your work

Answers

F and G are inverse if both of them satisfy the condition h(x)=x. f(g(x))=g(f(x))=x, as we discovered. The argument f(x) and g(x) are inverse functions is thus established.

How do you verify that f x and G x are inverses?

If f (x) and g (x) are inverse functions, it can be determined using one of two ways. For more information, see the explanation.

Explanation:

Instance 1

Inverse functions of both functions can be found using the first method.

Example.

Inverse of f (x) = x + 7 is what we're looking for.

We attempt to determine x using the equation y = x + 7.

y = x + 7

Inferring that g (x) is the inverse of f (x) from the fact that x = y 7

Finding g (x inverse )'s is now necessary.

g( x ) = x − 7

y = x − 7

x = y + 7

As a result, we discovered that f (x) is the inverse function of g (x).

f and g are equal if g is inverse of f and vice versa.

The second approach entails locating the compound functions f ( g ( x ) ) and g ( f ( x ) ). In this case, f and g are inverse if they are both h (x ) = x.

Example:

f ( g ( x ) =  [ x − 7 ] + 7

G ( x ) placed as x is the expression in brackets.

f ( g ( x ) ) = x − 7  + 7 = x

g (f ( x ) =  [ x + 7 ] − 7

f ( x ) inserted as x is the expression in brackets.

g ( f ( x ) ) = x + 7 − 7 = x

The equation f ( g ( x ) ) = g ( f ( x ) ) = x was what we discovered. The argument f (x) and g (x) are inverse functions is thus established.

To Learn more About inverse functions refer To:

https://brainly.com/question/3831584

#SPJ1

HURRY PLEASE 20 PTSSSS

HURRY PLEASE 20 PTSSSS

Answers

Answer:

1 -1

Step-by-step explanation:

thats what my school taught me if its wrong im sorry:)

Answer: 3/3 or 1

Step-by-step explanation:

So finding slope can be difficult but what you want to do is find the change in y and the change in x. So when I was looking at this you have to find something called the 'pretty point' where the line is perfectly on the corner of the square.

So look at (-2,-1) That is a "pretty point" now count right from there and go to your nect pretty point; (1, -1). Now that you have this information you know that our Run aka change in x is 3! Now do the same thing for our Rise, change in Y. You'll get 3 as well. With this information we know that our slope is 3/3 and you can also say 1.

In conclusion, you can say that the slope rises just as fast as it runs. I hope this is right for you I haven't done it in a while.

solve the inequality 1 - 2x + - 7​

Answers

Answer: x = -3 or if not solving for x then -2x -6

Step-by-step explanation:

1 - 2x - 7 = 0

-6 - 2x = 0

add 2x on both sides

-6 = 2x

divide 2 on both sides

-6/2 = x

x = -3

Refer to image and please attach working out

Refer to image and please attach working out

Answers

The solution to the initial value problem is determined as y = e³ˣ.

Form auxiliary equation

The auxiliary equation is determined as follows;

y'' - 7y' + 12y = 0

m² - 7m + 12 = 0

m² - 3m - 4m + 12 = 0

m(m - 3) - 4(m - 3) = 0

m = 3 or 4

\(y = c_1e^{3x} + c_2e^{4x}\\\\y(0) = 1\\\\1 = c_1e^{3\times 0} + c_2e^{4\times 0}\\\\1 = c_1 + c_2 \ --(i)\\\\y' = 3c_1e^{3x} + 4c_2e^{4x}\\\\y'(0) = 3\\\\3 = 3c_1e^{3\times 0} + 4c_2e^{4\times 0}\\\\3 = 3c_1 + 4c_2 \ \ --(ii)\)

solve (i) and (ii)

3 = 3c₁ + 4(1 - c₁)

3 = 3c₁ + 4 - 4c₁

3 = -c₁ + 4

c₁ = 1

c₂ = 0

\(y = e^{3x}\)

Learn more about initial value problems here: https://brainly.com/question/14744043

#SPJ1

How would you find the area of each of your rooms without furniture?

Answers

Given that you have a room that has dimensions l and w wherein l is the length of the room while w is the width of the room (shown in a diagram below).

the area of the room can be computed using the equation

\(A_{room}=l\times w\)

Basically, we just multiply the length and the width of the room.

How would you find the area of each of your rooms without furniture?

Rumus suatu fungsi di nyatakan dengan f (x) = 2x + 5. Jika f(a) = 7, nilai a adalah

Answers

Step-by-step explanation:

As my previous answer got deleted for being wrong (in which it was right), I will answer again.

The answer is 1. Why? Just plug it into the equation. F(1) = 2(1) + 5 = 7.

This is proof that it is right, and that there are some corrupt admins on brainly.

How to get to this solution?

Well notice how we are given what f(a) is. It is 2a + 5. So plug this in for f(a).

If we do so, we get 2a + 5 = 7.

Solving this equation, we get a = 1.

Find the area of the figure. Use 3.14 for it.
2 ft.
8 ft
3 ft
4 ft
3 ft
8 ft

Find the area of the figure. Use 3.14 for it.2 ft.8 ft3 ft4 ft3 ft8 ft

Answers

Answer:

I dont know if you still need it but the area of the figure is 51.5 ft2.

The area of the given figure is equivalent to 39.5 square feet.

What is Area?

Area is a collection of two - dimensional points enclosed by a single dimensional line. Mathematically, we can write -

V = ∫∫F(x, y) dx dy

Given is to find the area of the given figure as shown in the image.

We can write the area of the given figure as -

A{total} = A{Rectangle} + A{Δ1} + A{Δ2}

A{total} = (8 x 4) + (1/2 x 3 x 3) + (1/2 x 3 x 2)

A{total} = 32 + 4.5 + 3

A{total} = 39.5 square feet

Therefore, the area of the given figure is equivalent to 39.5 square feet.

To solve more questions on areas, visit the link-

https://brainly.com/question/29213222

#SPJ2

Simplify the polynomial, then evaluate for x = 2.
x+3x²+2x-3-4x²+6
x² + 3x + 9; 19
x² + 3x + 3; 5
-x² + 3x + 9; 11
O
O
-x² + 3x + 3; 13

Answers

Answer:

x^2 + 3x + 9 = (x + 3)(x + 3)

When x = 2, we have:

(2 + 3) * (2 + 3)

5 * 5

25

A bakery sold a total of 120 cupcakes in a day, and 66 of them were mocha flavored.
What percentage of cupcakes sold that day were mocha flavored?

Answers

Answer:

55%

Step-by-step explanation:

55% of the cupcakes were mocha flavored.

55% of the cupcakes where mocha flavored hope this helps u

Name three collinear points.

Name three collinear points.

Answers

Answer:

D, G and F  or I, G and J

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

Collinear points are the points on the same line.

There are two lines in the diagram.

The collinear points:

D, G and F on one lineI, G and J on the second line

The points that are collinear are  D,G and E  and another set of points which are collinear are L,G and J.

The points which lie on the same straight line are known as collinear points.

Similarly, if three or more number of points are collinear then they form a straight line.

If we observe the figure, the points D,G and E are collinear points as they are on same line.

Similarly the points L, G and H are in the straight line which makes them collinear.

Therefore , the points L,G and J are collinear points.

Hence, the points that are collinear are  D,G and E and another set of points which are collinear are L,G and J

To learn more on Coordinate Geometry click:

brainly.com/question/27326241

#SPJ1

Why does tire pressure change with temperature? Explain why the atoms are interacting in the certain way, How temperature plays a role in that interaction?​

Answers

Answer:

Temperature can change the volume of air.

Step-by-step explanation:

Tire pressure can decrease about 1 PSI for every 10 degrees the temperature drops. The air inside the tire condenses, taking up less space when it's cold. This is temporary because driving will heat up the tire and increase the tire's pressure.

3x^3-2x^2+7x+9 divided by x^2-3x

Answers

The quotient is 3x + 7, and the remainder is (28x + 9) / (x^2 - 3x).

What is Division?

A division is a process of splitting a specific amount into equal parts.

We have to find 3x³-2x²+7x+9 divided by x²-3x

3x³-2x²+7x+9 is the dividend and x²-3x is the divisor.

The steps to solve this are given below.

Step 1: Take the first digit of the dividend from the left. Check if this digit is greater than or equal to the divisor.

Step 2: Then divide it by the divisor and write the answer on top as the quotient.

Step 3: Subtract the result from the digit and write the difference below.

Step 4: Bring down the next digit of the dividend (if present).

Step 5: Repeat the same process.

Hence, the quotient is 3x + 7, and the remainder is (28x + 9) / (x^2 - 3x).

To learn more on Division click:

https://brainly.com/question/21416852

#SPJ9

3x^3-2x^2+7x+9 divided by x^2-3x

9. The (x+3)(x) is the factored form of the equation​

Answers

Answer: The answer is x²+3x

Step-by-step explanation:

hope that helps.

The answer is x^2+3x

Help

Classify each angle as acute,obtuse,right or straight.

HelpClassify each angle as acute,obtuse,right or straight.

Answers

Answer:

5. obtuse

6. acute

7. acute

8. acute

9. acute

10. acute

Step-by-step explanation:

sorry But the 5  might be right/straight  90 degress

Answer:

5. obtuse

6. acute

7. acute

8. acute

9. acute

10. acute

sorry But the 5  might be right/straight  90 degrees

Step-by-step explanation:

sorry But the 5  might be right/straight  90 degrees

Other Questions
Help me please Factorise:ax + bx - ay - by1: (a-b) (x-y)2: (a+b) (x+y)3: (a+b) (x-y)4: (a-b) (x+y) What body systems are related to taking in nutrients and expelling them from the body? A. nervous and circulatory B. digestive and circulatory C. digestive and excretory D. endocrine and excretory Choose the word or phrase that would best complete the following sentence. Read the paragraph, highlight key ideas, and _______________ notes in the margins.makebe makingmadewill make Can you please give me an alliteration slogans ? Find the annual interest rate. (Round your answer to the nearest whole number.) PLEASE HELP!!!FILL IN THE BLANKThe progressive movement was a ________ reform movement in the early-20th century. The following SQL statement selects all orders with an OrderDate between '04-July-1996' and '09-July-1996': http://www.w3schools.com/sql/sql_between.asp O SELECT * FROM Orders WHERE OrderDate BETWEEN #07/04/1996# AND #07/09/1996#;O SELECT CustomerName AS Customer, ContactName AS [Contact Person] FROM Customers;O SELECT * FROM Products WHERE ProductName BETWEEN 'C' AND 'M';O SELECT * FROM Products WHERE ProductName NOT BETWEEN 'C' AND 'M'; 1 2/15 + -3 1/2 in simplest form Daemon has an irrational fear of strangers. Even if someone on the road approaches him to ask the time, Daemon starts hyperventilating. Daemon's condition is termed as 1. You have set up a cell-free transcription system in a test tube. By mixing DNA, RNA polymerase, sigma factors, ribonucleotides and other essential substances you are able to make mRNAs identical to those made under a variety of conditions in the cells from which these components were isolated. What would happen if you were able to remove the sigma factor first added to the tube and replace it with another sigma factor Which of the following does not contributeto water pollution?A. factoriesB. farmsC. human and animal wasteD. education What is the equation of the following direct variation?y = -2xy = -xy = 2xy = x How much kinetic energy will an electron gain if it accelerates through a potential difference of 23,000 volts in a cathode ray tube? true or false? what is a clock. _______________________________ asserts that our genes set the boundaries within which we can operate, and our environment interacts with the genes to determine where in that range we will fall. Triangle PQR is dilated using the origin as the center to form the image triangle P'Q'R. Determine the scale factor used to make this transformation According to the law of large numbers, as more observations are added to the sample, the difference between the sample mean and the population mean _______. What is P(not divisor of 6)? 1. what is the difference between private and governmental not-for-profit organization and who oversees the accounting requirements for each type of organization? design and write a program that asks the user to enter a series of 20 numbers. the program should store the numbers in a list then display the following data: