Please help due today!

A weight-management researcher was interested in whether the size of breakfast could deter overall food consumption throughout the rest of the day. He creates two breakfast groups, a 350-calorie breakfast and a 750-calorie breakfast, assigns six participants to each group and tracks their total calories eaten in one day. Because of the detailed attention needed to accurately interview participants about their eating, he works with the high-calorie group and has his assistant interview the low-calorie group.

How many levels does the independent variable have in this study?

a. 1

b. 2

c. 6

d. It is impossible determine with the information given.

The correct answer is 2 (b)

Step-by-step explanation:

Variables are properties, of an experiment that take on different amount or values, unlike a constant that has one unchanging value assigned to it.

There are two kinds of variables; dependent and independent variables. Independent variables are variables that the scientist/experimenter has the power to manipulate at will. In our example, the independent variable is "the size of breakfast" because the experimenter chose by reason of will to either use 350-calories or 750- calories breakfast. While the dependent variables are variables whose outcomes are with respect to the change in the independent variable. The experiment is actually out to observe how the dependent variable plays out during the experiment. In our example, the dependent variable is "overall food consumption throughout the rest of the day". The outcome of the overall food consumption throughout the rest of the day is as a result of the size of breakfast taken.

Next, the independent variable can take on various levels, and the number of levels are the number of experimental conditions that the independent variables can take. In our example the independent variable (size of breakfast), was either 350-calories breakfast or 750-calories breakfast, hence it took 2 experimental conditions. Most of the time, 2 level independent variables are the independent and the control variables. For clarity, another example is; "a research to determine the effect of five kinds of body creams on the skin color after 2 years", the dependent variable is the skin color, while the independent variable is the type of cream and in this case there are five types of creams, hence the level of the independent variable is 5.

5 0

3 years ago

I think I know this much so far for A (but I could be wrong):

Eduardwww [97]

Part A. You have the correct first and second derivative.

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Part B. You'll need to be more specific. What I would do is show how the quantity (-2x+1)^4 is always nonnegative. This is because x^4 = (x^2)^2 is always nonnegative. So (-2x+1)^4 >= 0. The coefficient -10a is either positive or negative depending on the value of 'a'. If a > 0, then -10a is negative. Making h ' (x) negative. So in this case, h(x) is monotonically decreasing always. On the flip side, if a < 0, then h ' (x) is monotonically increasing as h ' (x) is positive.

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Part C. What this is saying is basically "if we change 'a' and/or 'b', then the extrema will NOT change". So is that the case? Let's find out

To find the relative extrema, aka local extrema, we plug in h ' (x) = 0
h ' (x) = -10a(-2x+1)^4
0 = -10a(-2x+1)^4
so either
-10a = 0 or (-2x+1)^4 = 0
The first part is all we care about. Solving for 'a' gets us a = 0.
But there's a problem. It's clearly stated that 'a' is nonzero. So in any other case, the value of 'a' doesn't lead to altering the path in terms of finding the extrema. We'll focus on solving (-2x+1)^4 = 0 for x. Also, the parameter b is nowhere to be found in h ' (x) so that's out as well.

6 0

3 years ago