Researchers randomly divide participants into groups. Each group takes a different amount of omega-3 fatty acid supplements daily for a month. One group receives a placebo. The researchers measure the impact on cholesterol levels in the blood. What is the purpose of random assignment in this experiment?
a. To ensure that all people with high cholesterol have an equal chance of being selected for the study
b. To increase the accuracy of the research results and prevent skewness in the data
c. To produce treatment groups with similar characteristics
d. To control confounding

b. To increase the accuracy of the research and prevent skewness in the idea.

Step-by-step explanation:

Random assignment ensures that any difference between groups recorded at the end of an experiment can be attributed to the experimental procedures. It refers to how you arrange the participants into required groups (different treatment and control groups). In the case of non-random assignment, the two major problems are generalisation of results and bias, which could lead to skewness in the idea of the experiment.

One of the importance of random assignment in this given experiment is to increase the accuracy of the research and prevent skewness in the idea.

a 4/6 = 9/12   not proportional

step-by-step explanation:

to find which are not proportional, we can use cross products

if it is true, they are proportional.   if it is not true, they are not proportional.

a 4/6 = 9/12

4* 12 = 6*9

48 = 54

not this is not proportional  

b 2/3 = 12/18  

2* 18 = 3 * 12

36 = 36

this is proportional

c 5/4 = 10/8  

5*8 = 4*10

40 = 40

this is proportional

d 7/5 = 35/25

7*25 = 5 * 35

175 = 175

is proportional

see explanation

step-by-step explanation:

a

(6r + 7) + (13 + 7r) ( remove brackets and collect like terms )

= 6r + 7 + 13 + 7r

= 13r + 20

b

remove brackets and collect like terms

13 - r - 1 + r

= 12 - r

c

remove brackets and collect like terms

= - 8 - r + 2r - 4

= - 12 + r

d

remove brackets and collect like terms

= 7r - - - 6r

[-   - = - - = - ]

= r -