Question 1117744: A directional hypothesis- A tanning lotion making you 2 shades darker.
Independent- 2 shades darker (color of skin)
Dependent- tanning lotion
Nondirectional hypothesis-a tanning lotion making you tan.
Independent- darker skin color
Dependent- tanning lotion
I think the more appropriate one would be the nondirectional in my opinion. I would be hard to make sure you skin color would be exactly 2 shades darker, since everyone skins color is different.
what would you say to this?
Answer by Theo(13342)   (Show Source):
You can put this solution on YOUR website! if the hypothesis is that the tanning solution makes you exactly 2 shades darker, then you can fail the test if the tanning solution makes you sufficiently less than 2 shades darker or the tanning solution makes you sufficiently more than 2 shades darker.
in that case, i would say that the test is non-directional since you can fail the test in either direction.
if the hypothesis is that the tanning solution makes you at least 2 shades darker, then you can fail the test if the tanning solution makes you sufficiently less than 2 shades darker only. you will pass the test no matter how many shades darker than 2 it makes you.
in that case, i would say that the test is directional.
it depends heavily on your alternate hypothesis.
if exactly 2 shades darker, then the test is non-directional since you can faile either lighter than 2 shades or darker than 2 shades.
i'm not exactly sure where dependent and independent come in.
i think the independent variable would be the tanning solution, since you decide how much of it to apply.
the dependent variable would have to be the amount of tanning, since that depends on the amount of tanning solution applied.
the amount of tanning solution that is applied would have to be tightly controlled, as well as how many applications are required in order to achieve 2 shades darker.
some suitable way to measure shades of tanning would also need to be used.
but, that's in the details.
the test passes if each sample is close enough to the control mean of 2 shades darker to allow you to determine that the differences are more then likely due to random chance, rather than intended effect.
that's where the confidence level comes in.
so, .....
if the test claims exactly 2 shades darker, then non-directional.
if the test claims greater than or equal to 2 shades darker, then directional.
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