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3 years ago

11

when a study is designed so that neither the subjects nor the experimenters know which subjects are in the treatment group and w

hich ones are in the control group, the study is called a ____ experiment.

2 answers:

Nata [24]3 years ago

5 0

(taken from a source)

<span>double blind
</span>
Hope this helped!

:)

Greeley [361]3 years ago

3 0

Answer:double-blind (APEX)

Step-by-step explanation:

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Mashcka [7]

Answer:

these are notes i wrote in geometry I'm not sure if this will help. it's been a few months since i did this

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3 years ago

In simplest radical form what are the solutions to the quadratic equation 0=-3x^2-4x+5

emmasim [6.3K]

Well first you have to find the solution, before you can put it in RADICAL FORM

3 0

3 years ago

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Write the equation of the line that

Misha Larkins [42]

Answer: y = -1/5x + 2

Work in pic:

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2 years ago

Determine if each statement is always, sometimes, or never true.

Iteru [2.4K]

Answer:

1) Parallel lines are "ALWAYS"

coplanar.

2) Perpendicular lines ARE "ALWAYS"

coplanar.

3) Distance around an unmarked circle CAN "NEVER" be measured

Step-by-step explanation:

1) Coplanar means lines that lie in the same plane. Now, for a line to be parallel to another line, it must lie in the same plane as the other line otherwise it is no longer a parallel line. Thus, parallel lines are always Coplanar.

2) similar to point 1 above, perpendicular lines are Coplanar. This is because perpendicular lines intersect each other at right angles and it means they must exist in the same plane for that to happen. Thus, they are always Coplanar.

3) to have the distance, we need to have the circle marked out. Because it is from the marked out circle that we can measure radius, diameter and find other distances around the circle. Thus, distance around an unmarked circle can never be measured.

8 0

3 years ago

It takes 3 hours to paddle a kayak 12 miles downstream and 4 hours for the return trip upstream. Find the rate of the kayak in s

Furkat [3]

The rate of the kayak in still water is 3.5 mph

<h3><u>Solution:</u></h3>

Given that It takes 3 hours to paddle a kayak 12 miles downstream

Distance covered in downstream = 12 miles

Time taken to cover downstream = 3 hours

Also given that it takes 4 hours for the return trip upstream

Distance covered in upstream = 12 miles

Time taken to cover upstream = 4 hours

<em><u>Formula to remember:</u></em>

If the speed of a boat in still water is u km/hr and the speed of the stream is v km/hr, then: Speed downstream = (u + v) km/hr and Speed upstream = (u - v) km/hr

Let the speed of Kayak in still water = x mph

And The speed of current = y mph

For downstream:

Speed downstream = x + y

We know that $speed = \frac{distance}{time}$

$\frac{distance}{time} = x + y$

$x + y = \frac{12}{3}$

x + y = 4 ------ eqn 1

<em><u>For upstream:</u></em>

Speed upstream = x - y

$\frac{12}{4} = x - y$

x - y = 3 -------- eqn 2

Now let us eqn 1 and eqn 2

Add eqn 1 and eqn 2

x + y + x - y = 4 + 3

2x = 7

x = 3.5

speed of Kayak in still water = x mph = 3.5 mph

6 0

3 years ago