An experiment was conducted to evaluate the success of a methicillin-resistant Staphylococcus aureus (MRSA) vaccine. MRSA can be prevented if subjects regularly wash their hands. The subjects were treated, but only some of the vaccines were successful. The researchers are unsure whether this was a result of hand washing or the vaccine alone. What is this an example of?
A. Confounding
B. The placebo effect
C. Blinding
D. Replication
E. Bias

a

Confounding

Step-by-step explanation:

There are two variables that could have lead it being successful, thus the variables are confounding.

b.an increase in a causes b to decrease

d) by the cross product property, ab^2 = bc multiplied by ad

step-by-step explanation:

we are given

in the given triangle abc

angle a is 90° and segment ad is perpendicular to segment bc

we can see that

triangle(abc) and triangle(abd) are similar because they have common side and same angle (90 degree)

so, triangles(abc) and abd are similar

since, they are similar

so, the ratio of their sides must be equal

we get

now, we can cross multiply

and we get

so, this could be step to prove it