1. Researchers recruited over 1,000 patients with chronic back pain to participate in a study about the benefits of acupuncture. Each subject was randomly assigned to one of these treatment
plans: traditional Chinese acupuncture, placebo acupuncture, and conventional pain treatment of
medication and physical therapy.
What is the primary purpose of randomly assigning subjects to the different treatment plans?
(2 Points)
To increase confounding variables
To create groups that are as similar as possible so the main difference between the groups is the
treatments
To control against nonresponse
To ensure both the subjects and researchers are blind to who is in which group
To reduce the impact of sampling variability

the answer is d

the answer is in the first quadrant, which make the y-int positive.

since the dots are going down, therefore the correlation is negative

i hope it is right.

logv3(x+2)=1

rewrite in exponential form:

logb(x) = y is equal to b^y =x

b = 3, y = 1

now solve for x:

3^1 = x+2)

x = 3-2

x = 1

see the picture for the graph.

2. angles qrt and qst both measures 156 degrees.

step-by-step explanation:  

we have been given a diagram of a circle and we are told that measure of arc qvt is 156 degrees.  

we can see from our given diagram that angle qrt and angle qst subtends to arc qvt.

since we know that angles subtended by the same arc at the circumference are always equal.

by angle subtended by same arc theorem, measure of angle qrt and angle qst will be equal to the measure of arc qvt.

therefore, angles qrt and qst both measures 156 degrees and 2nd statement is the correct choice.

the answer is c.

step-by-step explanation: