elect all the correct answers.
A group of scientists is conducting an experiment on the effects of media on children. They randomly select 100 children and randomly assign each child to one of four treatment groups. Each treatment group has a specific amount of screen time during a one-week time frame. The first group has no screen time, the second group has two hours of screen time, the third group has four hours of screen time, and the fourth group has six hours of screen time.

After the first week, the scientists conduct the same experiment, with the same subject groups, for three more weeks so that each group experiences each of the four treatments.

Which statements about this study are true?

This study uses blinding.
This study uses blocking.
This study uses a control group.
This study uses a repeated measures design.
This study uses random sampling.

Answer:

its 0.00001

I hope this helps

Answer:

160

Step-by-step explanation:

39 + 125 = 164

164 rounds to 160

Answer:

160

Step-by-step explanation:

39+125​=164

164 rounded=160

Hope this helps :)

Answer:

32

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

Answer:

  (a) a function, but not one-to-one

Step-by-step explanation:

The graph is of a function if it passes the vertical line test: a vertical line intersects the graph in at most 1 point.

The function is one-to-one if it passes the horizontal line test: a horizontal line intersects the graph in at most 1 point.

__

Here, the graph consists of a series of non-overlapping horizontal lines. It passes the vertical line test (is a function), but a horizontal line can intersect the graph in an infinite number of points (is not one-to-one).

The graph is a function, but not one-to-one.

Answer:

x=-22.42

Step-by-step explanation:

-18.43=3.99+x

Move the variable to the left-hand side and move the constant to the right. Change their signs.

-x=3.99+18.43

Add.

-x=22.42

Change the signs on both sides of the equation.

x=-22.42

Hope this helps :)

Answer:

Its 34 times 87

Step-by-step explanation:

34 times 87 is 2958

Answer:

1799 members in the art club i think but i don't have a bar graph

Step-by-step explanation:

^^

Answer 1/614

Step-by-step explanation:

Answer:

11/9 OR 1 and 2/9

Step-by-step explanation:

5/9 + 4/6

get like deonimators by mutiplying top and bottom by same thing --- afterall mutiplying by 2/2, 3/3, 4/4.. etc is mutiplying by 1... not changing anything!

So:

(2/2)*(5/9) + (3/3)(4/6) =  10/18 + 12/18 = 22/18

Which can be simplified :)

11/9 ORRR 1 and 2/9

Step-by-step explanation:

rules? I like get brainlist pleaseee :00 it's totally A

Answer: 27 tickets a+k

Step-by-step explanation:

11+16

Answer:

2:1  or  2

Step-by-step explanation:

*** (Ratios can be written as " a : b", or can be written as a fraction " a / b".

 >> therefore 10/5 can be simplified to 2/1 )***

    For every 10 notebooks, there are 5 ballpens.

    Therefore, for every 2 notebooks there is 1 ballpen (The simplification).

EXTRA:  

**Also remember that the ratio of notebooks to ballpens cannot be reversed into ballpen to notebook ratio, because this would change the meaning.

  2/1 is not the same as 1/2 **

Answer:

28% are green or red

Step-by-step explanation:

Answer:

B

d(P,Q) = sqrt((xO-xQ)^2 + (yP-yQ)^2) = sqrt(16+9) = 5

Answer:

3 1/3 is already in the simplest form. It can be written as 0.230769 in decimal form (rounded to 6 decimal places).

Have an awesome day! :D

Answer:

5.235 (Simplifies as $5.24)

Step-by-step explanation:

1 gal = 20 miles

1.5 gal = 30 miles

1 gal = $3.49

1.5 gal = $5.235

Answer:

9 mm

Step-by-step explanation:

90*0.1=9

Step-by-step explanation:

=> 2x-1/4 + x/3 = 2

=> 3(2x-1) +4x / 12 = 2

=> 6x -3 + 4x = 24

=> 10x = 27

=> x = 2.7

Answer:

x = 27/28

Step-by-step explanation:

Solve 2x-1/4 + x/3 = 2

2x - 1/4 + x/3 = 2

2x + (-1/4) + 1/3x = 2

(2x + 1/3x) + (-1/4) = 2

7/3x + (-1/4) = 2

7/3x = 9/4

3/7 * 7/3x = 3/4 * 9/4

x = 27/28

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

check

2 * 27/28 - 1/4 + 27/28 *1/3 = 2

2 = 2

the answer is good

Answer:

Formula for Volume of a Trapezoidal Prism. If the prism length is L,trapezoid base width B, trapezoid top width A, and trapezoid height H, then the volume of the prism is given by the four-variable formula: V(L, B, A, H) = LH(A + B)/2. In other words, multiply together the length, height, and average of A and B.Step-by-step explanation:

Answer: $420

To find the total simple interest over the two years, we first find 5/100 (5%) of 200 which is 10. That’s the interest of 1 year so we multiply that by 2 to get 20 for 2 years. Each year a deposit of $200 is made so over two years $400. $20 add $400 is $420 which is the total.

Answer:

8/90

Step-by-step explanation:

hope this helps

Answer:

It's 38/45

Step-by-step explanation:

I don't really have a step-by-step explanation. I just looked it up! ;) good luck

9514 1404 393

Answer:

  8,500 units

Step-by-step explanation:

The contribution margin from each unit is ...

  $185 -121 = $64

To accumulate a total contribution that will cover the fixed costs and the desired income, you require sales of ...

  ($416,000 +128,000)/($64/unit) = 8,500 units

Answer:

331.02

Step-by-step explanation:

Answer:

what did they do?

Step-by-step explanation:

Answer:

2.7

Step-by-step explanation:

1200x 30/100×25/100×3/100=2.7

Step-by-step explanation:

the numbers : x, y

x + y = 65

x = y + 5

we use the second equation in the first equation :

y + 5 + y = 65

2y + 5 = 65

2y = 60

y = 30

x = y + 5 = 30 + 5 = 35

If the given equation is

[tex]27^{\frac13} = 9^{14} + 3^{x + 1}[/tex]

first simplify the left side using the fact that 27 = 3³:

[tex]27^{\frac13} = (3^3)^{\frac13} = 3^{\frac33} = 3^1 = 3[/tex]

and on the right side, 9 = 3²:

[tex]9^{14} = (3^2)^{14} = 3^{2\times14} = 3^{28}[/tex]

So we have

[tex]3 = 3^{28} + 3^{x + 1}[/tex]

Next,

[tex]3^{x+1} = 3^x \times 3^1 = 3 \times 3^x[/tex]

so that

[tex]3 = 3^{28} + 3 \cdot 3^x[/tex]

and dividing both side by 3 gives

[tex]1 = 3^{27} + 3^x[/tex]

Isolate 3ˣ :

[tex]3^x = 1 - 3^{27}[/tex]

Solve for x by taking the base-3 logarithm of both sides:

[tex]\log_3(3^x) = \log_3(1-3^{27})[/tex]

[tex]x \log_3(3) = \log_3(1-3^{27})[/tex]

[tex]\boxed{x = \log_3(1-3^{27})}[/tex]

Answer:

Step-by-step explanation:

0 = 5x + 7

-7 = 5x

x = - 7/5 = -1.4

Answer:

-1.4

Step-by-step explanation:

h(x)=0=5x+7

or, 5x= -7

x= -7/5= -1.4