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uranmaximum [27]
3 years ago
9

In one study on the effect of argan oil on wrinkles, 125 subjects who acknowledged being long-time argan oil users had their wri

nkles compared with those of 125 people who had never used argan oil. In a second study, 75 subjects were chosen randomly to use argan oil and 75 were chosen to use a placebo. Identify the types of studies performed. (4 points)
Mathematics
1 answer:
brilliants [131]3 years ago
6 0

Answer:   The first study was an observational study whereas the second was a controlled experiment.

Step-by-step explanation:

A study that record the characteristics of a population by studying individuals in a sample, but does not manipulate variables of interest is known as an operational study. Like in the first study only effects have been noted.

A controlled experiment is an experiment where the variable of interest is directly manipulated by a scientist, in order to test a single variable at a time.

Like in the second study, the subjects were under the control of the experimenter, to test the effect of oil.

The first study was an observational study whereas the second was a controlled experiment.

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wolverine [178]

Answer:

1100 cookies

Step-by-step explanation:

There are 3 types of cookies, the first represents 45% of the total, the second 25% and the last type there are 330. We can pose the following equation:

0.45 * x + 0.25 * x + 330 = x

solving for x:

x - 0.45 * x - 0.25 * x = 330

0.30 * x = 330

x = 330 / 0.3

x = 1100

which means that there are a total of 1100 cookies

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3 years ago
First to answer gets brainliest
skad [1K]

Answer:

Step-by-step explanation:

Because you can't do -x+1 so it would be (1,0) and then you have x^2 +3x-4 which is (-5,6)

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3 years ago
A volleyball reaches its maximum of 13 feet, 3 seconds after it is served. What quadratic formula could model the height of the
Katena32 [7]

Answer:

H=-(t-3)^2+13

Step-by-step explanation:

The path covered by the volleyball will be a downward parabola with the vertex being the highest point of the ball.

A general form of a downward parabola is given as:

y=-a(x-h)^2+k

Where (h,k) is the vertex of the parabola and 'a' is a constant.

Now, let 'h' be the vertical height and 't' be the time taken.

So, the equation would be of the form:

H=-a(t-h)^2+k

Now, as per question:

h = 2 seconds, k = 13 feet.

H=-a(t-3)^2+13

Now, taking a = 1. So, the formula that can be used is:

H=-(t-3)^2+13

7 0
3 years ago
Give an example of how people have used igneous rock. PLSS GIVE ME EXAMPLE PLSSSs
bogdanovich [222]

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Granite is a one of the most common igneous rock. Its used in building materials and making statues.

Step-by-step explanation:

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Fill in the blanks to solve 900 x 6
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Answer:

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