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fiasKO [112]
3 years ago
9

At a local health club, a researcher samples 75 people whose primary exercise is cardiovascular and 75 people whose primary exer

cise is strength training. The researcher’s objective is to assess the affect of type of exercise on cholesterol. Each subject reported to a clinic to have his or her cholesterol measured. The subjects were unaware of the purpose of the study, and the technician measuring the cholesterol was not aware of the subject’s type of exercise. This approach is
a)

an observational study.
b) an experiment, but not a double-blind experiment.
c) a double-blind experiment.
d)

fundamentally flawed because only a well-designed experiment with randomized assignment to treatments can be used to determine a cause-and-effect relationship.
Mathematics
2 answers:
ivolga24 [154]3 years ago
8 0

Answer:

A

Step-by-step explanation:

Basically, this is an observational study because the researcher does not apply any treatment.

It's not an experiment because there is no experimentation involved. :)

It's not double-blind because in that case the researcher would have to apply something to two kinds of groups. one aware one the other not. not the case.

It's not D because  The observations are comparing two kinds of subjects and they are not looking for a cause and effect.

Andrei [34K]3 years ago
7 0

Answer:

a) an observational study.

Step-by-step explanation:

This is an example of an observational study. An observational study refers to a study in which a researcher draws inferences from a population without interfering with it. In this case, the independent variable is not under the control of the researcher. This is an example of an observational study because the researcher is simply measuring the effect of each type of training, as opposed to interfering with the subjects.

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Answer:

1/5 cup

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Please explain how to do this, I'm using all my points<br><br>A. 40 L<br>B. 80 L<br>C. 4 L <br>D. 8L
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Answer: choice A. 40 liters

====================================

Explanation:

x = number of liters of the 50% alcohol solution

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So far we have 0.50*x + 36. This expression represents the total amount of pure alcohol. We want a 70% solution, so we want 70% of the total 40+x meaning 0.50*x + 36 is to be set equal to 0.70*(40+x) and we solve for x as shown below

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Please help with math (30 points)
ikadub [295]

Here we have some problems about circles, the solutions are:

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<h3>How to find the area of a circle?</h3>

We know that for a circle of diameter D, the area is given by:

A = pi*(D/2)^2

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In the image we can see that the diameter of the circle is 25 yd, replacing that in the area equation we get:

A = 3.14*(25yd/2)^2 = 490.6 yd^2

<h3>How to find the value of x?</h3>

<u>For the second image</u>, each line creates two 180° angles. So, if we look at the tilted line, we can see that it is divided in two angles, one of 37° and the other that depends of x, so we can write:

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For the last image:

Notice that we have a 90° angle denoted, then <u>the other 3 sections must add up to 270°.</u>

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If you want to learn more about circles, you can read:

brainly.com/question/25306774

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