A set of quiz scores has a mean of 78 and a standard deviation of 9. Using a common grading scale where 60 and above is a passing score, what percentage of the
students passed this test?
Explain your answer in terms of the 68-95-99.7 rule.

Answers

Answer 1

Answer:

97.5% of the students passed this test.

Step-by-step explanation:

The Empirical Rule states that, for a normally distributed random variable:

Approximately 68% of the measures are within 1 standard deviation of the mean.

Approximately 95% of the measures are within 2 standard deviations of the mean.

Approximately 99.7% of the measures are within 3 standard deviations of the mean.

In this problem, we have that:

Mean of 78, standard deviation of 9.

What percentage of the  students passed this test?

Above 60.

60 = 78 - 2*9

So 60 is two standard deviations below the mean.

The normal distribution is symmetric, which means that 50% of the measures are above the mean and 50% are below.

Of the 50% above, all passed.

Of the 50% below, 95%(within 2 standard deviations of the mean) passed.

So

[tex]p = 0.5 + 0.5*0.95 = 0.975[/tex]

97.5% of the students passed this test.


Related Questions

If ABCD is dilated by a factor of 3, the
coordinate of C' would be:
5
c
B
2
-6 -5 -4 -3 -2 -1 0
2
3
4
5
-1
-2
A
D
C' = ([?],[])
--3

Answers

The new coordinate for C would be 1,2.

A regular hexagon has a radius of 20 in. What is the approximate area of the hexagon?

600 in.2
1,038 in.2
1,200 in.2
2,076 in.2

Answers

Answer:

B

Step-by-step explanation:

A=(3*sqrt(3)*a^2)/2

A=(3*sqrt(3)*400)/2=1038

Answer:

B.  1,038 in.2

Step-by-step explanation:

I need helppppp!!!!!!!!

Answers

Answer:

√124

Step-by-step explanation:

Using the Pythagorean theorem, We got: x^2 + (√101)^2 = 15^2

x^2 + (√101)^2 = 15^2

x^2 = 15^2 -  (√101)^2

x^2 = 225 - 101

x^2 = 124

x = √124

The answer is √124

Which equation represents a line with a slope of 3 that passes through the point (5,2)? Show all work

(A) y=3x-13

(B) y=3x+17

(C) y=3x-1

(D) y=3x+2

Answers

Answer:

A

Step-by-step explanation:

use the equation y-1=m(x-x1)

the slope is the same as the m which is the gradient

x1 is 5 and y1 is 2.the x and the y are constants

replace the values given in the equation

y-2=3(x-5)

y-2=3x-15

y=3x-13

I hope this helps

Oliver invested $970 in an account paying an interest rate of 7 1/2 % compounded continuously. Carson invested $970 in an account paying an interest rate of 7 3/8% compounded annually. To the nearest of a hundredth of a year, how much longer would it take for Carson's money to double than for Oliver's money to double?

Answers

Answer:

0.50 or about half a year longer.

Step-by-step explanation:

We can write an equation to model bot investments.

Oliver invested $970 in an account paying an interest rate of 7.5% compounded continuously.

Recall that continuous compound is given by the equation:

[tex]A = Pe^{rt}[/tex]

Where A is the amount afterwards, P is the principal amount, r is the rate, and t is the time in years.

Since the initial investment is $970 at a rate of 7.5%:

[tex]A = 970e^{0.075t}[/tex]

Carson invested $970 in an account paying an interest rate of 7.375% compounded annually.

Recall that compound interest is given by the equation:

[tex]\displaystyle A = P\left(1+\frac{r}{n}\right)^{nt}[/tex]

Where A is the amount afterwards, P is the principal amount, r is the rate, n is the number of times compounded per year, and t is the time in years.

Since the initial investment is $970 at a rate of 7.375% compounded annually:

[tex]\displaystyle A = 970\left(1+\frac{0.07375}{1}\right)^{(1)t}=970(1.07375)^t[/tex]

When Oliver's money doubles, he will have $1,940 afterwards. Hence:

[tex]1940= 970e^{0.075t}[/tex]

Solve for t:

[tex]\displaystyle 2 = e^{0.075t}[/tex]

Take the natural log of both sides:

[tex]\ln\left (2\right) = \ln\left(e^{0.075t}\right)[/tex]

Simplify:

[tex]\ln(2) = 0.075t\Rightarrow \displaystyle t = \frac{\ln(2)}{0.075}\text{ years}[/tex]

When Carson's money doubles, he will have $1,940 afterwards. Hence:

[tex]\displaystyle 1940=970(1.07375)^t[/tex]

Solve for t:

[tex]2=(1.07375)^t[/tex]

Take the natural log of both sides:

[tex]\ln(2)=\ln\left((1.07375)^t\right)[/tex]

Simplify:

[tex]\ln(2)=t\ln\left((1.07375)\right)[/tex]

Hence:

[tex]\displaystyle t = \frac{\ln(2)}{\ln(1.07375)}[/tex]

Then it will take Carson's money:

[tex]\displaystyle \Delta t = \frac{\ln(2)}{\ln(1.07375)}-\frac{\ln(2)}{0.075}=0.4991\approx 0.50[/tex]

About 0.50 or half a year longer to double than Oliver's money.

Solve the following system of equations by graphing. Label the solution and all intercepts.
4x-2y=8
y=1/2x+2
Please show me also how to graph it. Thanks a ton!

Answers

Answer:

(4,4)

y = 4

x = 4

Step-by-step explanation:

First we need to input y = 1/2x + 2 into 4x - 2y = 8.

4x - 2 (1/2x + 2) = 8 <-- Then solve

4x - 1x + -4 = 8

3x - 4 = 8

    +4   +4

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

3x    =    12

3             3

x = 4

Now we need to use x and apply it to find y.

y = 1/2x + 2

y = 1/2(4) + 2

y = 2 + 2

y = 4

Now to graph go on the x axis (horizontal axis) and go to 4, then up 4 on the y axis.

You need to graph the point (4,4).

I hope this helps!

Answer:

see graph  (4,4)

to manually graph just pick any two values for X in the first equation and calculate the corresponding Y value ... put a "dot" (a point on the graph)

do for both points , and draw al LINE between them...

repeat fore the second equation... the "solution" is where the two lines cross

Step-by-step explanation:

4x-2y=10
y=-2x-5

A.(-1,-3)
B.(-1,-6)
C.(3,1)
D.(-3,-1)

Answers

Answer:

D.-3,-1 for 4x-2y=10 y=2x-5

Divide

(16x^2 + 16x^3 –6x)➗(6x–2)​

Answers

ANSWER: [tex]\frac{8x^2}{3} + \frac{32x}{9} +\frac{5}{27} +\frac{10}{27(6x-2)}[/tex]

GOOD LUCK, I hope this helped!

Write the expression as a complex number in standard form.

( 7 - 4i ) + ( 8 + 6i )


(Please don't spam anything for points, and could you leave an explanation as well? Thanks!)

Answers

Answer:

15+2i

Step-by-step explanation:

Hi there!

We are given the following expression:

(7-4i) + (8+6i)

And we want to write it as a complex number in standard form

Standard form is a+bi, where a is the real part of the number and bi is the imaginary part of the number.

We can open up the parentheses on the expression

7-4i+8+6i

Now combine the like terms (add 8 and 7 together, then add -4i and 6i together)

15+2i

The complex number is now in standard form

Hope this helps!

Determine the value of x.


Question options:

A) 72.64 units


B) 12.86 units


C) 16.66 units


D) 1.11 units

Answers

Answer:

Step-by-step explanation:

The 48 degree angle is our reference angle. The side measuring x is opposite that reference angle, and the side measuring 15 is adjacent to that reference angle. That means we need the trig ratio that uses the sides opposite and the side adjacent, which is tangent; namely:

[tex]tan48=\frac{x}{15}[/tex] and solve for x by multiplying both sides by 15 to get

15tan48 = x so

x = 16.66 units

Answer:C

Step-by-step explanation:

Guys please help me find the answer

Answers

Given

Value of Boat = $23,000

Rate = 18% per year

Time = 5 years

y = 23000(1-18/100)⁵

= 23000(82/100)⁵

So y = 23000 (0.82)

x = 5

Answered by Gauthmath must click thanks and mark brainliest

Un chip tiene un espesor de 0,12 mm y un atomo de cobre mide 0,00000000133 m.¿cuantos atomos se necesita para alinearlos en el espesor de un chip de celular uno a continuacion de otro

Answers

Answer:

El espesor de un chip es de 0.12mm

Y el diámetro de un átomo de cobre, mide aprox:

0.00000000133 m

Queremos saber cuantos átomos deberemos alinear de tal forma que la "cadena" de átomos de cobre mida 0.12mm

Eso es equivalente a ver cuantas veces entra 0.00000000133 m en 0.12mm

Primero, escribamos ambos valores en las mismas unidades, sabiendo que:

1m = 1000mm

Podemos reescribir:

0.00000000133m = 0.00000000133*(1000 mm) = 0.00000133mm

Entonces tenemos que ver cuantas veces entra 0.00000133mm en 0.12mm

Esto sera igual al cociente entre 0.12mm y  0.00000133mm, esto es:

N = (0.12mm)/(0.00000133mm) = 90,225.6

Redondeamos al próximo número entero:

N = 90,226

Esa es la cantidad de átomos que se necesitan.

If m ≠ 1 and mn - 3 = 3 - n , then what is the value of n?
A) 6/ m+1
B) 6/ m-1
C) 6/ m+n
D) 6/ m-n

Answers

[tex]n = \frac{6}{m + 1} [/tex]

Hope it helps you...

The value of n is n= 6/( m+1).

What is expression?

An expression is a set of terms combined using the operations +, – , x or , /.

Given:

mn - 3 = 3 - n

mn + n = 6

n(m+ 1) =6

n= 6/( m+1)

Learn more about expression here:

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Help Please!!!
Find the volume of the triangle prism?

Answers

Answer:

Formula of a triangle:

B(base)H(height) x 1/2

Area of triangle:

8(base) x 13(height) x 1/2(basically just dividing by 2) = 52(area of triangle)

Now we multiply by the actual height of the whole thing

52(area of triangle) x 11(height) = 572 cm3 is your answer.

Answer:

area of base= B=1/2 bh

=1/2×8×13

=52

height of prism=11

volume of prim= Bh

=52(11)

=572 cm³

OAmalOHopeO

If there were 36 candies and only 12 children, how many candies would each child get?

Answers

Answer:

3 each

Step-by-step explanation:

36 / 12 = 3

.................................................

each would get 3 pieces

Solve the inequality 12(1/2 x - 1/3) > 8 - 2x

O A. x>-1
O B. x > 3
O C. X>1/2
O D. x>3/2

Answers

Answer:

[tex]D. \\x>\frac{3}{2}[/tex]

Step-by-step explanation:

12(1/2x - 1/3) > 8 - 2x

6x - 4 > 8 - 2x

6x + 2x - 4 > 8 - 2x + 2x

8x - 4 > 8

8x - 4 + 4 > 8 + 4

8x > 12

8x ÷ 8 > 12 ÷ 8

x  > 1.5

PGCPS ALGEBRA 1 CR (SUMMER 2021) 793023

Solve the equation

Use the equation solver to find the value of x that

makes the mathematical statement true.

1. For parentheses:

Distribute

O 0.5

0Bx93 94-03-17

63x93 126-17

• 17x

17x

O 0.5

2 If necessary

Combine Terms

O 0.87

O 1.5

23 Bx9326

-93 -93

2388

- 119

• 238

• 238

2. Apply properties:

Add Subtract

Multiply

Divide

05

To start over

Reset

You have solved the equation

Show Me

(1) Intro

✓ Done

Previous Activity

1 of 10

Answers

Answer:

See explanation

Step-by-step explanation:

The texts in the question is distorted and unclear; So, I will provide a general explanation of solving an equation with 1 variable.

A similar question that can be found online is:

[tex]8x - 8 = 4x + 12[/tex] --- to solve for x

First, collect all like terms

[tex]8x - 4x = 8 + 12[/tex]

Distribute the expression on the left-hand side

[tex]x(8 - 4) = 8 + 12[/tex]

[tex]x * 4 = 8 + 12[/tex]

Simplify like terms

[tex]x * 4 = 20[/tex]

Divide both sides by 4

[tex]x = 5[/tex]

What is the length of BC? Round to the nearest tenth.

Answers

Answer:

BC ≈ 14.5 cm

Step-by-step explanation:

Using the sine ratio in the right triangle

sin65° = [tex]\frac{opposite}{hypotenuse}[/tex] = [tex]\frac{BC}{AB}[/tex] = [tex]\frac{BC}{16}[/tex] ( multiply both sides by 16 )

16 × sin65° = BC , then

BC ≈ 14.5 cm ( to the nearest tenth )

In a triangle ABC, angle BAC = 53° and angle ACB = 28°. If AB is produced to D, find angle CBD.​

Answers

Angle CBD= 81°

I hope it helps you...

Answer:

81

Step-by-step explanation:

∠CBD is the exterior angle of  the ΔABC.

Exterior angle property:

Exterior angle equals the sum of opposite interior angles.

∠CBD = ∠ABC + ∠ACB

           = 53 + 28

           = 81°

HELPPPP me I need help don’t know the answer

Answers

It’s c because when the number of simply it gets u that

Answer:

All, if you're not defining the angles.

Step-by-step explanation:

The angle ACB/BCA is 55 degrees, ACE/ECA is 125 degrees, DCE/ECD is the same as ACB/BCA, and BCD/DCB is the same as ACE/ECA

Can someone explain and give an example of spurious correlation?

Answers

Answer:

A spurious correlation wrongly implies a cause and effect between two variables. For example, the number of astronauts dying in spacecraft is directly correlated to seatbelt use in cars: Use your seatbelt and save an astronaut life!

Interesting correlations are easy to find, but many will turn out to be spurious. Three examples are the skirt length theory, the Super Bowl indicator, and a suggested correlation between race and college completion rates.

Step-by-step explanation:

A basketball team received a care package and split it evenly among
5 players. If each player received 9 candy bars, how many candy bars
were in the care package?

Help please

Answers

Answer:

45

Step-by-step explanation:

9x5

Do you remember how to solve a multistep linear equation with variables on both sides? Review with a Quick Check.

Solve:
5(a−1)−15=3(a+2)+4

Answers

Answer:

Step-by-step explanation:

5(a-1) -15 = 3(a+2) +4, distribute multiplication over subtraction and addition

5a -5 -15 = 3a +6 + 4, isolate the variable on one side

5a -3a = 6 +4 +5 +15, combine like terms

2a = 30, divide both sides by 2

a= 15

Suzy has some stickers and a sticker album. if she pastes 7 stickers on each page, she will need 21 more stickers. If she pastes 11 stickers on each page, she will need 81 more stickers. how many pages are there in Suzy's sticker album​

Answers

Answer:

15 pages

Step-by-step explanation:

let x be the number of pages

7x-21 = 11x-81

4x = 60

x = 15

Find the missing side lengths

Answers

Answer:

x = 11√3

y = 11

Step-by-step explanation:

Let 60 be the reference angle

sin 60 = p/h

√3/2 = x/22

or, 22√3 = 2x

or, x = (22√3)/2

so, x = 11√3

now

[tex]h^2 = p^2 + b^2\\or, 22^2 = (11\sqrt{3} )^2+y^2\\or, 484 = 363 + y^2\\or, 484-363 = y^2\\or, 121 = y^2\\or, \sqrt{121} = y\\so, y = 11[/tex]

If today is Tuesday, May 6, this year July 4 will fall on a _____
(A) Sunday
(B) Monday
(C) Thursday
(D) Friday

Answers

Answer:

July 4th will fall on Sunday

The date, July 4 will be Friday, the correct option is D.

What are Calendars?

Calendars represent an year of 12 months, each month has 30 or 31 days, exceptionally February has 28 days.

If today is Tuesday, May 6,

Every 7th day is going to be a Tuesday .

From May 6 to July 4, the number of days is 59

Hence we divide 59 by 7. Quotient = 8 Remainder = 3

7 x 8 = 56

56 th day is Tuesday

57 th day is Wednesday

58th day vis Thursday

59th day is Friday

To know more about Calendars

https://brainly.com/question/656246

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Round 74.164 to the nearest whole.

Answers

Answer:    [tex]\bf 7\underline4 . 164 \approx 74[/tex]

Step-by-step explanation:

Answer:

74

Step-by-step explanation:

Keep in mind you're rounding rules!

PLEASE HELP ME! I REALLY NEED HELP

Answers

Answer:

a)

(i) 5.8 hours

(ii)  6.5 hours

(iii) 6 hours

(iv) 6 hours

b) 180 hours

Final
Lines L and M are parallel.
34
2/5
16
38° 7
-L
>M
Find : m_6
Cotor the

Answers

Answer:

38

Step-by-step explanation:

Angle 6 is alternate to the angle that is given as 38 degrees because line L is parallel to line M so their measure is equal.

Please help me answer this question thank you :)

Answers

Answer:

A.

[tex]f(x) = \frac{ \sqrt[3]{x} }{5} \: { \bf{and}} \: g(x) = 5 {x}^{3} [/tex]

Step-by-step explanation:

Consider f(x) as the original function:

[tex]{ \tt{f(x) = \frac{ \sqrt[3]{x} }{5} }}[/tex]

Let the inverse be m:

[tex]{ \tt{g(x) = f {}^{ - 1} (x) = m}} \\ { \tt{m = \frac{ \sqrt[3]{x} }{5} }} \\ { \tt{5m = \sqrt[3]{x} }} \\ { \tt{x = 5m {}^{3} }} \\ therefore : \\ { \tt{g(x) = 5 {x}^{3} }}[/tex]

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