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.

the length of o'p' is .

step-by-step explanation:

it is given that the quadrilateral m'n'o'p' is the image of quadrilateral mnop after dilation.

the center of dilation is origin and the scale factor is 1.5.

in dilation the image and preimge are similar figures. it means the sides of image and preimage are proportional.

the scale factor is defined as

the scale factor is 1.5.

multiply both sides by op.

note: if the value of op is given, then multiply the value of op with 1.5 to get the length of side o'p'.

therefore length of o'p' is .

the answer is d=3.09