A college chemistry teacher wants to know whether taking a practice
exam will help her students score higher on their final exam. She
randomly selects 50 students from among the four sections of
Introductory Chemistry that she teaches. Then she randomly divides
them into two groups of 25 students each. Group A will take a practice
exam, and group B will not take a practice exam. After all 50 students
take their final exam, she will compare their results.
Which of these are the treatments in this experiment?
A. Taking a morning chemistry class and taking an afternoon
chemistry class
B. Having taken high school chemistry and not having taken high
school chemistry
C. Being one of the 50 students selected and not being one of the 50
students selected
D. Taking a practice exam and not taking a practice exam

Answers

Answer 1
https://brainly.com/question/17278316
Answer 2

the answer is option b


Related Questions

the cross sectional area of this circular duct is 226.865 square inches.

what would be the diameter of the duct

Answers

Answer:

D. 17

Step-by-step explanation:

No-

If the range of the function f(x) =5x + 8 is 18, find its domain.​

Answers

Step-by-step explanation:

f(X) = 5x+18= 18

so,

18 = 5x+18

18-18 = 5x

X= 0

so domain of the function is 0

REALICE LOS SIGUIENTES PROBLEMAS DE ECUACIÓN DE LA RECTA CORRECTAMENTe

1.- Encuentre la ecuación vectorial de la recta si tenemos A(4, -2) y el vector V=(2, 5) paralelo a la recta y que pasa por A


2.- Encuentre la ecuación general de una recta conociendo un punto P(-2 ; 4) y su pendiente m= - 5 y grafique la recta.

Answers

Answer:

1. La ecuación vectorial de la línea es [tex]\begin{bmatrix} & x & \\ & y & \end{bmatrix} =\begin{bmatrix} & 4 & \\ & -2 & \end{bmatrix} + t \times \begin{bmatrix} & 2 & \\ & 5 & \end{bmatrix}[/tex]

2. La ecuación de la recta es, y = -5·x - 6

Step-by-step explanation:

 1. El punto dado en la línea es A (4, -2), el vector paralelo a la línea es (2, 5)

Por tanto, la ecuación vectorial de la línea es;

[tex]\begin{bmatrix} & x & \\ & y & \end{bmatrix} =\begin{bmatrix} & 4 & \\ & -2 & \end{bmatrix} + t \times \begin{bmatrix} & 2 & \\ & 5 & \end{bmatrix}[/tex]

Donde;

t = Cualquier número

2. El punto por el que pasa la recta es P (-2; 4)

La pendiente de la recta, m = -5

Por lo tanto, la ecuación de la línea en forma de punto y pendiente se presenta de la siguiente manera;

y - 4 = (-5) · (x - (-2)) = -5 · x - 10

∴ y - 4 = -5 · x - 10 + 4 = -5 · x - 6

La ecuación de la recta es, y = -5·x - 6

I NEEDDDD HELPPPP ITS URGENTTTT!!!!!!

Answers

radius: (-3, 7)
center: 11

Have fun all !!! This is my trash account. You all can have my points.

Answers

Answer:

Step-by-step explanation:

OK

Answer:

rshjgdlf

FGshjfgsfds

Step-by-step explanation:

GIMME'

What are the solutions to the quadratic equation 3(x - 4)2 = 75?
O x = -9 and x = 1
O x = -5 and x = 5
O x = -4 and x = 4
O x = -1 and x = 9

Answers

Answer:

4th option, x = -1 and x = 9

Step-by-step explanation:

3(x-4)²=75

or, (x-4)²=25

or, x²-8x+16-25=0

or, x²-8x-9=0

or, x²-9x+x-9=0

or, x(x-9)+1(x-9)=0

or, (x-9)(x+1)=0

so, x-9=0 or, x=9

and x+1=0 or, x=-1

The two solutions of the quadratic equation are:

x = -1 and x = 9

How to solve the quadratic equation?

The quadratic equation is:

3*(x - 4)^2 = 75

We can expand it as:

3*x^2 - 3*2*4*x + 3*16 = 75

3x^2 - 24x  -27 = 0

Now, using Bhaskara's formula we get:

[tex]x = \frac{-(-24) \pm \sqrt{(-24)^2 - 4*3*(-27)} }{2*3} \\\\x = \frac{24 \pm 30 }{6}[/tex]

So the two solutions are:

x = (24 + 30)/6 = 9

x = (24 - 30)/6 = -1

If you want to learn more about quadratic equations:

https://brainly.com/question/1214333

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Last question, thank you guys a lot for helping me out

Answers

Answer: Her earnings after taxes will be $415.80 (choice C)

How?

PER 1 HOUR: 0.77 x (13.50 x 1) = 0.77 x $13.50 = $10.395

PER 40 HOURS: 0.77 x (13.50 x 40h) = 0.77 x 13.50 x 40 = $415.80

what is the volume of the cone below?​

Answers

Answer:

96 pi

Step-by-step explanation:

The formula for the volume of a cone is V=pi*r^2*h/3 the radius is 4 and the height is 18 plug in those values into the equation to get V=pi*16*6 16*=96 so the answer is 96 pi.

Answer:

Volume = 96π cu. units

Step-by-step explanation:

Cone volume = πr^2h/3 where r = radius and h = height

V=π(4)^2(18)/3

V=π(16)(18)/3

V=π288/3

V=96π

Someone help pleasee

Answers

Answer:

-80

Step-by-step explanation:

We can write the quadratic as

ax^2 + bx+c

4x^2 +8x+9

a=4  b = 8  c=9

The discriminant is

b^2 -4ac

8^2 - 4(4)(9)

64 - 144

-80

Answer:

-80

Step-by-step explanation:

The discriminant is the value under the radical in the quadratic formula. The part of the quadratic formula that is under the radical is [tex]\sqrt{b^2-4ac}[/tex]. So, plug in the needed values and solve for what is under the radical. The b-value is 8; this squared is 64. Then, plug in a and c, 4 and 9. Then multiply these by 4, 4*4*9=144. Finally subtract, 64-144=-80.

PLZZZ HELPPP, IF NOT 100% SURE PLZ DONT ANSWER…BRAINLIEST TO FIRST AND CORRECT ANSWER, THX TO SECOND AND CORRECT ANSWER

Answers

Answer:

1

Step-by-step explanation:

add 1/2 + 1/2 = 2/2 = 1

a positive integer n is called special if n is divisible by 4, N+1 is divisible by 5 and n+2 is divisible by 6. how many special integers smaller than 1000 are there?​

Answers

Answer:

17

Step-by-step explanation:

these positive integers are :

4, 64, 124, 184 ... , 964

964 = 4 + (n-1) (60)

964 = 4 + 60n -60

964 = 60n -56

60n = 1020

n = 1020/60

n = 17

so, the number of special integers smaller than 1000 are = 17

The digits n, n+1 and n+2 implies that the special numbers are consecutive i.e. they follow one another. The count of special numbers less than 1000 is 17.

Given that:

[tex]\{n,n+1,n+2\} = \{4,5,6\}[/tex]

[tex]Range = 1000[/tex]

First, calculate the LCM of 4, 5 and 6.

[tex]4 = 2 \times 2[/tex]

[tex]5 = 5[/tex]

[tex]6 = 2 \times 3[/tex]

So, the LCM is:

[tex]LCM = 2 \times 2 \times 5 \times 3[/tex]

[tex]LCM = 60[/tex]

This means that the special digit occurs after every other 60 digits (i.e. the difference between a special digit and another is 60)

To calculate the count of special digits, we make use of arithmetic progression formula

[tex]L = a + (n - 1) \times d[/tex]

Where

[tex]L = 1000[/tex] --- the last term

[tex]a = 4[/tex] --- the first special digit

[tex]d = 60[/tex] --- the common difference as explained above

So, we have:

[tex]L = a + (n - 1) \times d[/tex]

[tex]1000 = 4 + (n - 1) \times 60[/tex]

Collect like terms

[tex]1000 - 4 =(n - 1) \times 60[/tex]

[tex]996 =(n - 1) \times 60[/tex]

Divide both sides by 60

[tex]16.6 =n - 1[/tex]

Add 1 to both sides

[tex]1 + 16.6 =n[/tex]

[tex]17.6 =n[/tex]

Rewrite as:

[tex]n =17.6[/tex]

Remove the decimal part (do not approximate)

[tex]n =17[/tex]

Hence, the special numbers are 17 in total (that are less than 1000).

Read more about arithmetic progression at:

https://brainly.com/question/21093837

find the common difference

Answers

9514 1404 393

Answer:

  (a)  1/12

Step-by-step explanation:

The difference of adjacent terms is ...

  1/4 -1/6 = 3/12 -2/12 = 1/12

The answer is 1/12!!!

Rachel has 37 videos and decides to purchase 2 more each week. Write an equation describing this situation.

Answers

Answer:

T = 2w + 37

Step-by-step explanation:

Let T represent the total amount of videos Rachel has after w weeks

Rachel already owns 37 videos

She purchases 2 more each week

Therefore, after w weeks, the total amount of videos Rachel has can be represented by the expression:

2w + 37

Then the total after w weeks can be modeled by the equation:

T = 2w + 37

The diameter of a $1 coin is 26.5 mm. Find the area of one side of the coin. Round to the nearest hundredth.

Answers

The area of one side of the coin is 41.605 mm².

Given that, the diameter of a $1 coin is 26.5 mm.

We need to find the area of one side of the coin.

What is the area of a circle formula?

The area of a circle formula is A=πr².

Now, radius=26.5/2=13.25 mm.

Area of a coin=3.14×13.25=41.605 mm².

Therefore, the area of one side of the coin is 41.605 mm².

To learn more about the area of the circle visit:

https://brainly.com/question/11952845.

#SPJ2

A jazz band wants to sell $6,558 worth of tickets. If each ticket costs $6, how many tickets will the band have to sell to meet its goal?

Answers

Answer:

1093 tickets

Step-by-step explanation:

Take the total amount and divide by the amount per ticket to determine the number of tickets

6558/6

1093 tickets

Answer:

The band have to sell 1093 Ticket to meet its goal

Step-by-step explanation:

Total cost = $6,558

Per Ticket cost =$6

formula:

No of Tickets = Total cost of Ticket ÷  Per Ticket Cost

                       = 6558 ÷ 6

No of Tickets = 1093

Check:

Total Cost = No of Ticket × Per ticket cost

                 = 1093 × 6

Total Cost =$6558

Find the missing side of triangle

Answers

Final Answer:

x = 20

Step-by-step explanation:

we'll be using the pythagorean theorem method, in this triangle the missing letter is a.

formula: [tex]a=\sqrt{c^2-b^2}[/tex]

a = x

b = 21

c = 29

a = [tex]\sqrt{29^2-21^2}[/tex]

a = [tex]\sqrt{841-441}[/tex]     (note: 29² = 29 × 29 = 841 and 21² = 21 × 21 = 441)

a = [tex]\sqrt{400}[/tex]

a = 20

x = 20

The quotient of 3 and a number x

Answers

Answer:

3/x

Step-by-step explanation:

Quotient is a division.

3/x

What is the mean of the set of data?
6, 7, 10, 12, 12 ,13
answer choices:
6
10
7
11​

Answers

Answer:

mean = 10

Step-by-step explanation:

The mean is calculated as

mean = [tex]\frac{sum}{count}[/tex]

         = [tex]\frac{6+7+10+12+12+13}{6}[/tex]

        = [tex]\frac{60}{6}[/tex]

       = 10

7.

Which kind of function best models the data in the table? Graph the data and write an equation to model the data.


A. exponential; y = 3x – 1

B. linear; y = x – 1

C. quadratic; y = x2 – 1

D. linear; y = –x – 1

Answers

Answer:

D. linear; y = –x – 1

Step-by-step explanation:

Linear; y=-x - 1

The slope is negative since it’s decreasing. So it’s not the first equation. It’s not a quadratic equation because there is no forming U shape for this data. It’s not a exponential function because the slope is not 3 and a exponential function is in the form y=a(b)^x

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

Answer:

The correct answer is D) linear; y = –x – 1

Step-by-step explanation:

To find this, use any values in the table and it will produce a true statement. This is how we check to see if a model is correct. See the two examples below for proof.

(4, 5)

y = -x - 1

-5 = -4 - 1

- 5 = -5 (TRUE)

(0, -1)

y = -x - 1

-1 = 0 - 1

-1 = -1 (TRUE)

find square. root of 85849.​

Answers

Answer:

293

Step-by-step explanation:

✓85849=. 85849^1/2

= 293

Let f(x) = x2 − 1 and g(x) = 3x. Find gf and state its domain

Answers

Step-by-step explanation:

here's the answer to your question

Answer:

[tex]g(x) \times f(x) = 3{x}^{3} -3x[/tex]

X exists for all real numbers.

Y exists for all real numbers.

pls help, and explain. Will give brainliest

Answers

Cost of 12 notebooks = $9

Ratio of number of notebooks to its price

= 12:9

= 4:3 (because we reduced it to the simplest form by dividing both numerator and denominator by 3)

Let the cost of 8 notebooks be x.

Then, 8:x = 4:3

=> 8/x = 4/3

=> (8×3)/4 = x

=> 24/4 = x

=> 6 = x

So, the cost of 8 notebooks is $6.

Jerome solved the equation below by graphing. log Subscript 2 Baseline x + log Subscript 2 Baseline (x minus 2) = 3 Which of the following shows the correct system of equations and solution?

Answers

Answer:

B. on edge 2021

Step-by-step explanation:

y 1 = StartFraction log x Over log 2 EndFraction + StartFraction log (x minus 2) Over log 2 EndFraction, y 2 = 4; x = 4

Answer:

It's B :))

Step-by-step explanation:

What is 4 1⁄2 cm in millimetres

Answers

Answer:

the answer is 205 millimeters

Answer:

205 millimeters.

Step-by-step explanation:

just is

Refer to picture
Need help on Q.8

Answers

Answer:

Rajan = 436.36 rupees and Kamal = 363.63 rupees

Step-by-step explanation:

Total ratio = 11/30

Amount to be shared = 800

Rajan = Individual ratio / Total ratio x the total amount to be shared

1/5 ÷11/30 × 800 = 436.36

Kamal = 1/6 ÷ 11/30 × 800 = 363.63

Tính : 2020^3-1/2020+2021

Answers

Answer:

2020³-1/4041

Step-by-step explanation:

GIVING BRAINLIEST. GRAPH ABSOLUTE VALUE INEQUALITY y<-1/3|x+4|+5

Answers

Answer:

-1/3 · Ix+4I + 5

or

y∠ - Ix+4I -15

            3

Step-by-step explanation:

hope this helped

Gabriella has a smart phone data plan that costs $25 per month that includes 10 GB of data, but will charge an extra $15 per GB over the included amount. How much would Gabriella have to pay in a month where she used 5 GB over the limit? How much would Gabriella have to pay in a month where she used went over by x x GB?

Answers

I believe the answer would be 75+25= so $100

Find the area of the shaded region.

Answers

Answer:

pi × 18cm^2

Or approximately,

56.52cm^2 (using 3.14 for pi)

or

56.5487cm^2 (using pi button on calculator)

Step-by-step explanation:

Area of a circle is pi times [radius squared].

All circles are 360°.

Problem can be solved by finding area of whole circle, and then using ratios.

Whole Circle: area = pi × (9cm)^2 = pi × 81cm^2

80° / 360° = Area[shaded] / (pi × 81cm^2)

pi × 18cm^2 = Area[shaded]

((If you read my answer before the edit, I am sorry. I made a calculator error.))

4) In the proof below, what is the missing reason?

Answers

9514 1404 393

Answer:

  (c)  CPCTC

Step-by-step explanation:

Even if you don't know the meaning of CPCTC, you can eliminate the other choices because they refer to the whole triangle, not two corresponding angles.

Angles B and D are corresponding angles in the congruent triangles. The reason they are congruent is ...

  Corresponding Parts of Congruent Triangles are Congruent (CPCTC)

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