2. Researchers want to test if a new medicine will help people who have trouble falling asleep. To determine if the medicine works, they give it to 100 volunteers who report having
trouble sleeping. After using the medicine for one week, the volunteers will report back on
how the medication worked.

Explain how a control group and a placebo could have been used and why that is important.

answer: the answer is b. i think hope i got it correct

step-by-step explanation:

(x) - (y) = (1 + 4i)

answer:   the paragraph proof is mentioned below.

step-by-step explanation:

given: in a δxwy where

such that, ∠wzx ≅ ∠yzx and zw≅zy

we have to prove that: segment zx is a perpendicular bisector of segment wy.

prove: since, zw≅zy ⇒ ∠wzy is a supplementary angle.

then, ∠wzy= 180°

⇒∠wzx + ∠yzx = 180° ( because xz divides ∠wzy into two parts)

but, ∠wzx ≅ ∠yzx ( given)

⇒∠wzy+∠wzy=180° ( by substitution)

⇒2∠wzy=180°

⇒∠wzy=90°

⇒∠wzy=∠yzx =90°

therefore, xz⊥wy where wz=zy

⇒zx is a perpendicular bisector of wy.